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The Planting and Care of 

Shade Trees 




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New Jersey 
Forest Commission 



FOREST PARK RESERVATION COMMISSION 
OF NEW JERSEY 



ft 



The Planting and Care of 

SHADE TREES 

By Alfred Gaskill, State Forester, 



INCLUDING PAPERS ON 



Insects Injurious to Shade Trees 

By John B. Smith, State Entomologist, 



AND 



Diseases of Shade and Forest Trees 

By Mel. T. Cook, State Plant Pathologist. 



TRENTON, N. J. 

State Gazette Publishing Co., Printers. 

1912. 



r^^^^ 
^ ^ 



The Forest Park Reservation Commission. 



I-Iou. AVOODROW WILSON, Governor, ex-officio President. 
HENRY B. KUMMEL, Trenton, Executive Officer. 
ELMER H. SMITH, Salem. 
CHARLES L. PACK, Lakewood. 
WILLIAM ^Y. SMALLEY, Bound Brook. 



ALFRED GASKILL, Trenton, Forester and Secretary. 
JAjMES .0. HAZARD, Trenton, Assistant Forester. 
CHARLES P. WILBER. Trenton, State Firewarden. 
Office, State House, Trenton. 



lEC h' 



"V 



2G 

or 



i Illustrations. 

PAGE. 

Fig. 1.— Elms 30 years old ^5 

Fig. 2. — Too much shade ^ 

Plate I. — Shade trees good and bad 11 

Fig. 3. — Residence street insufficiently shaded 12 

Fig. 4. — Street newly planted 15 

Fig. 5. — Diagram — How trees should be placed 10 

Fig. G. — Young tree as received from the nursery IS 

Fig. 7. — Same with top and roots pruned IS 

Fig. 8. — Diagram — How to plant a street tree 20 

Plate II. — Types of tree guards and gratings 

Fig. 9. — Exposed roots tolerable 

Fig. 10. — A tree choked by a guy wire 

Fig. 11. — Guard a tree thus if it must anchor a guy 27 

Fig. 12. — Trees guarded while building goes on 28 

Fig. 13. — How lack of system gives a poor effect 31 

Fig. 14. — Trees on curb and inside footway contrasted 33 

Fig. l.j. — Old trees on a new grade and with cabled wires through 

their crowns 34 

Fig. 16. — Abrasion movilding 36 

Fig. 17. — Dense crowned Norv\-ay maple 37 

Fig. 18. — Norway maple after an interior pruning 37 

Fig. 19. — Butchered maples 40 

Fig. 20. — Diagram — How to doctor a tree 42 

Fig. 21. — Cavities from untreated wounds 44 

Fig. 22. — Pruning wounds completely healed 44 

Plate III. — Tree wounds filled and unfilled 47 

Fig. 23. — Trees saved by mounding and raising curb 50 

Fig. 24.— A tree "well"' 51 

Fig. 25. — Street grade raised without injuring trees 51 

Fig. 26. — Trees in gutter and on sidewalk 54 

Fig. 27. — A w-ell shaded lawn made from native forest near the sea. 55 

Fig. 28. — Street lines accommodated to shade trees 58 

Fig. 29. — Elm standing in roadway 60 

Fig. 30.— Trees left above grade 62 

Plate R'. — Insects injurious to shade trees 70 

Plate Y. Insects injurious to shade trees 71 

Fig. 31. — The maple pseudococcus 77 

Fig. 32.— The San Jose scale 79 

Fig. 33.— A soft scale 81 

Fig. 34. — The maple-tree sesiid 82 

Fig. 35. — Work of the hickory bark beetle 85 

Fig. 36. — Chestnut leaf spot 95 

Fig. 37.— Chestnut tree nearly dead of blight 100 

Fig. .88. — Section of chestnut killed by blight 101 

Fig. 39. — White pine blister rust 104 

Fig. 40. — Fomes igniarius 108 

Fig. 41. — Polyporus sulfureus 110 

Fig. 42. — Polystictus versicolor 113 

Fig. 43. — Armillaria mellea 115 



Introductory. 



The iirst two of this series of papei:s, with one on Fungi 
of Xative and Shade Trees, by Dr. Bjron D. Halsted, were 
originally published in the report of the Forest Park Reserva- 
tion Commission of Xew Jersey for 1908. Appreciative de- 
mands having exhausted the edition, Mr. Charles Lathroi) 
Pack, a member of the Forest Commission, and a well known 
pioneer in Forest Conservation, generously offered to de- 
fray the cost of a new issue. This offer was accepted and the 
Forest Commission has caused two of the papers to be thor- 
oughly revised and a new one dealing with tree diseases to be 
prepared by the recently appointed State Plant Pathologist. 

The State is committed to the policy of protecting, improv- 
ing and increasing the number of its shade trees. This btil- 
letin is published under the direction of the 

'- ...-,■. Authority. 

Forest Park Reservation Commission with the 
co-operation of the Trustees of the State Agricultural Ex- 
periment Station. Each paper is by an acknowledged au- 
thor! tv in his line. 




Fig. 1. Elms ;-50 years old, well placed, well spaced, well guarded. (Courtesy of 

U. 8. Forest Service.) 



Shade Tkees. 

The reader is reminded that none of the 

Scope. . „ . 

papers pretends to be exhaustive ot its subject; 
each deals in the briefest possible waj^ with the things that 
concern the trees of the State, and aims to tell what to avoid 
as well as what must be done. The bulletin will serve as a 
manual to those who are accustomed to working with trees, 
and Avill guide those who seek to travel an unknown, though 
it may be an attractive, path. More detailed information 
will be found in the books listed on page 123, though for any 
important work tree owners are advised to seek the assistance 
of a reputable tree planter, tree doctor, arborist or forester. 
The Agricultural Experiment Station and the .Forest Com- 
mission have lists of such and will furnish them upon request. 
assistance Both offices are prepared to give advice by 

offered. mail Oil any matter relating to trees, and, when 

necessary, either will have a competent man make an ex- 
amination aud report. Any municipal body, as a shade tree 
commission, or the managers of a public institution, will be 
aided without charge; individuals will ordinarily be re- 
quired to pay the consultant's expenses, but not his salary. 



The Planting and Care of Shade 

Trees. 

By Alfked Gaskill and Ja^ies O. Hazard, Foresters. 

I^ew Jersey is fortunate in having a soil and climate so 
favorable that many species of trees can be grown in any part 
of it, or some species found for almost any situation. It 
must be ure'ed, hov^^ever, that only a few trees con.utious 

. , • T,' • 1 l^^T favorable 

vv^ithstand the trying conditions imposed by „„,! „„. 
city streets and buildings, or the rigors of the 
sea coast. Attention is, therefore, given chiefly to street 
trees, for the number which may be grown successfully on 
any well kept lawn, even in a city, is very great. Upwards 
of forty species are found in more or less thrifty condition 
on the street, parking and lawns within two blocks of the 
State I-Touse, and many more might be planted that would 
do as well. 

Street Trees. 

There is little use trying experiments with trees for^ street 
planting. At the best, a tree on a city street is out of its ele- 
ment and at a disadvantage ; chose, therefore,^ amongst the 
few that are known to thrive under your conditions, get good 
trees, plant them carefully, and take care of them. 

REQUIREMENTS. 

A street tree should be chosen for its (1) Form, (2) Hardi- 
ness or AdaptaUlitv, (3) RapidHy of Growth, (4) Shade 
Production, (5) Neatness, (6) Beauty; the various qualities 
ranking in about the order given. 

1. Form is placed first because, no matter how good the 



8 - Shade Teees. 

tree, il is a failure if it does not fit the situation. By careful 
pruning almost any tree can be made to grow upright, or to 
develo]:» a broad crown, but it is much better to chose a species 
that naturally takes the desired form. Trees are beautiful, 
or otherwise, as they harmouize with their surroundings. 

On narrow streets with houses close to the curb only slen- 
der trees of moderate height growth should be planted. I\ed 
maple, red gum, ginkgo, are good. For wider streets, or 
those with parking in front of the houses, larger trees like 
T^orway maple, basswood, horse chestnut, or pin oak, may 
be chosen. Wide avenues should be dignified with the most 
majestic trees — ^white elm, white oak, red oak, tulip poplar. 

2. Hardiness and Adaptability are qualities of prime im- 
portance in a street tree. Under any circumstances care- 
ful consideration must be given to the native soil, the pave- 
ment, the nearness of buildings, as well as to the vigor of 
the tree itself and its ]:)ower to adapt itself to unusual strains. 
Strength to withstand the pressure of wind, snow, ice, etc., 

abilitv to recover from mechanical iniuries, and 

A street . " , . ., 

tree must resistaucc to insect attack and to disease are also 

be resistiiut. , 

factors. JNo tree at all susceptible to frost 
should be j3lanted in this State. Sweet gum grows well in 
clay but not in sand ; sugar maple and basswood suffer from 
leaf burn when over a smooth, light colored pavement; horse 
chestnut is apt to be infested with insects and fungi. 

3. Bapidify of Groivth. To most people who plant trees 
that which grows most rapidly is best. Thus our streets are 
filled with silver maples, box elders and cottonwoods instead 
of JSTorway maples, oaks and elms. Quick growing trees are 
desirable, yet it is a fact that those which grow most rapidly 
Qiiiek are commonly the shortest lived. Plant silver 
trees are maple Or cottouwood if you must have a good 
lived. sized tree in a hurry, but don't forget that it 
will have to be replaced when a jSTorway maple, a red oak, or 
a sycamore is at its" best. And bear in mind that cultivation 
and care will make any good tree grow comparatively rapidly. 
A red oak well nurtured will increase in size faster than a 
maple that is neglected and abused. 



Stkeet Tekes. 




Fig. 2. A good row of trees but houses too much shaded. 
See Figs. 4 and 14. 

4. Shade Production. On many streets it is easily pos- 
sible to have too much shade. (Fig. 2.) Houses and side- 
walks need sun e^'en in summer ; therefore, on narrow streets 
trees Avith light foliage, like the locusts and ashes, Avill usually 
be better than the denser crowned maples, etc. Early leafing 
is never desirable. 

5. Neatness. A tree is a nuisance Avhen it litters the street 
with its bloom or fruit, sends up many suckers, heaves the 
pavement by its superficial roots, emits an offensive odor, or 
attracts insects. Cottonwoods or poplars are, 
therefore, to be avoided because, among other tunt are 
reasons, they cover the ground with their bloom 

in the spring ; silver maples will break up any pavement ; 
ailanthus has a very bad smell for several weeks each year 
unless the trees bear pistillate flowers only; mulberry has a 
fruit which when crushed makes the sidewalks slippery and 
dangerous. 



10 ' Shade Trees. 



PLATE I. 

Shade Trees Good and Bad in one New Jersey City. 

A. Extreme Neglect ; the Pole Looks Better Than the Tree. 

B. No Tree can Thrive Where the Pavement is so Close. 

C. A Street Tree that is Bad in Every Way ; It Forlis too low 
and has no growing space. 

D. A Worse than Useless Guard. It is too low to prevent horse- 
biting, and so small that the tree is choired. 

E. A Newly-planted Tree Protected by a Guard that is Entirely 
too Light, and with no Growing Space. 

F. A Guard Outgrown and Sidewalk Displaced by Root Growth. 

G. A Good Temporary Guard, but too Light to last Long. Grow- 
ing space much too small. 

H. A Good Guard but Evidently not Placed Until After the 

Tree had been Badly Injured by Horses. Growing space en- 
tirely too small. 

I. A Tree Well Guarded and Well Provided with Growing 

Space. 

J. A Thriving Street Tree. It has a fair growing space and is 

sufficiently guarded with wire. 

K. A Growing Space like that Provided for this Tree Interferes 

Little with the Footway. 



''■s^-^'-'M 




j<^b=c^-==403^==^])==^, 







Plate I. See descrijjtions opposite. 



1 '> 



Shade Tkees. 



6. Beauty. The idea of beauty in a tree is satisfied when 
it is normal in form, vigorous in growth, healthy, and suitably 
placed. Street trees always suffer by contrast with those in 
natural situations, yet when arranged harmoniously in well- 
spaced rows, the uniformity of the trees matching the uni- 
,^ ^ . formity of the street, most satisfactory results 

Uniformity. "^ . , ' '' 

are obtained. This rule demands that all the 
trees on a street, or at any rate all in a block, shall be of the 
same kind and as near alike as possible in size and shape. 
See -Figs. 1 and 4. 

In choosing shade trees, it is always proper to consider the 
buds, twigs, flowers, fruit and coloring of the leaves. The 
pendant, spiky balls of the red gum are as at- 
tractive through the winter as its brilliantly 
colored leaves in the fall. Of all the trees fit for street plant- 
ing the most gorgeous are the maples in their autumn dress. 
The spring beauty of the horse chestnut in bloom is largely 
offset by its dilapidated appearance in early autumn, when 
most other trees are still fresh. 



Fruits, 

flo^vers, 

color. 




Fig 3. A residence street insufficiently shaded. See Figs. 4 and 26. 



Steeet Teees, 



13 



WHAT TO PLANT. 

The list of trees cajDable of meetiag the conditions in a 
citj street is not long; it might indeed be cnrtailed to less 
than a dozen. . Evergreens are excluded altogether because 
their shade is not wanted in winter. The fol- Evei-sreeus 
lowing list is arranged to show the trees best ex<?i"de<i- 
adapted to streets of various v/idths and includes all the 
species, foreign as well as native, which are in any way 
suitable, except perhaps on wide streets where lawn condi- 
tions are approached. Those at the top of each column are 
preferred to those farther down. See pages 56 to 65 for 
descriptions of each species. 



The Best Teees foe City Stbeets. 



JVarroio Streets. 
(less than GO feet 
wide between building 
lines.) 

Ginkgo 
Red Gum 
Red Maple 
Norway Maple 
Honey Locust 
Hackberry 
Green Ash 



Average Streets. 
(60 to 90 feet wide 
between building- 
lines.) 

Norway Maple 
Red Gum 
Pin Oak 
Red Oak 
Scarlet Oak 
Red Maple 
Sj'camore 
Bass wood 
Hackberry 
White Ash 
Ginkgo 

Honey Locust 
Horse Chestnut 
Sugar Maple 



Wide Streets. 
(over 90 feet wide 
between building 
lines. ) 

White Elm 
Red Oak 
Scarlet Oak 
Sycamore 
Sugar Maple 
White Oak 
Tulip Poplar 
Basswood 
Red Gum 
Ailanthus 



Trees not recommended. From the foregoing list several 
trees universally found on city streets Avill be missed. Silver, 
or white, maple is a rapid grower and able to survive many 
handships, yet its youthful beauty is soon lost by the breaking 
of its fragile branches and a general early decay. It is also 
prone to disturb the pavement by the growth of superficial 
roots. The pojilars or cottonwoods, of Avhich there are several 
species, are even more rapid growers than the silver maple 



14 Shade Teees. 

when 2^] anted in rich, moist soil, and their slender habit 
adapts them well to narrow streets, bnt they are even shorter 
lived than the maple, are offensive by the litter that they make 
Trees to "^ spring and by the many root suckers that 

"^**"* they produce. For these reasons they are ex- 

cluded from the streets of Albany, IS^. Y., by a city ordi- 
nance. In ^Vashington, D. C, the silver maples and poplars 
planted years ago are being replaced by other species. Wil- 
lows have no recommendations whatever as street trees. 
N'one of these trees, therefore, should be planted unless it 
be for a m.omentary effect. Twenty years after planting, any 
of the trees recommended will be in better form and, if w^ell 
chosen and properly cared for, almost as large. Black locust 
should not be planted solely because it is sure to be injured 
or destroyed by the borer worm. Except for this fault it 
makes a fine tree for narrow streets on account of its hardi- 
ness, narrow crown and fine foliage. Beech is a slow grower 
and casts too dense a shade for any street. It is further 
objectionable for any public place because its smooth bark 
tempts every jackknife carver. Walnut and the hicJcories in- 
vite injury by their fruit and, therefore, have no place as 
street trees. Chestnut is sure to fall a prey to the bark 
disease, see page 101. 



PLANT THE TREE THAT SUITS LOCAL CONDITIONS. 

Any of the trees here recommended will grow in every part 
of the State but, after meeting other conditions, a careful 
planter will chose that whose natural habitat is nearest like 
the planting site. If the soil be very dry chose scarlet oak, 
hackberry, honey locust rather than white ash, white elm or 
jN^orway maple. If it be clay, red gum, pin oak or sycamore 
A close re- will be apt to do best. By changing the soil 
between soil natural couditious can often be modified so that 
and tree. ^j^^ preferred species may be planted. Any soil 

but the very best should be enriched when a tree is planted, 
for the needs of the tree are apt to be forgotten afterwards. 



Street Trees. 



15 



THE TIME TO PLANT. 

Deciduous trees should never be transplanted while the 
leaves are on. Midwinter is not a good time because the 
ground is apt to be frozen. Late fall is often preferred, yet 
it is never well to expose a tree to the dangers of a winter be- 
fore it has had a chance to srow new roots and ^ . , ^ 

c? , Siirins' best 

fix itself in the soil. In this State early spring, "/nnt*** 
just after the ground thaws, is by far the best 
season. Trees are then quick with new life and if moved 
can very promptly provide feeding organs and adapt them- 
selves to changed conditions. If a drouth follows the plant- 
ing, and spring drouths are common, the trees must be freely 
watered until thev are established. 



ARRANGEMENT ON THE STREET. 

Uniformity. When planting is done by the property 
owners individual choice will naturally have the widest 
range — as to species, size, location and everything else. But 
everv effort should be made to have all the trees on a street 




Fig. 4. A residence street newly plcanted with Norway Maples, well grown 
and well placed. (Courtesy of the Newark Shade Tree Commission.) 

the sanie kind, the same size, and uniformly spaced. (See 
Figs. 1 and 4.) Where the building lots are of various 



16 



Shade Tkees. 



widths uniform spacing is sometimes difficult, but there is 
no need to place trees in the same position in front of every 
house. 

Spacing. Do not plant trees so close together that when 
gro^^Ti thev will interfere or entirely shade the house fronts. 
Too much shade is as bad as too little, and each tree should 
have room to develop its own form. (Fig. 4.) In blocks 
made up of lots 20 feet wide, or less, a tree should be planted 
in front of every other house only, those on opposite sides 
being alternated thus : 




Fig. 5. How trees should be placed on a narrow street. 

On wider streets, 40 feet, 50 feet, 60 feet or even more 
may be given to a tree according to its size and habit of 
growth, and the arrangeinent may be opposite or alternate ac- 
cording to conditions. But in every case the aim should be to 
develop rows, or blocks, of trees, rather than individuals. A 
quick effect can be secured by planting trees closely, and as 
they grow removing the alternate ones. But a very practical 
difficulty, apart froin the cost, is that no one wants to thin 
them out at the proper time. If close planting is resorted 
to the intervals must he half or one-third the intended ulti- 
mate spacing. 



Street Tkees. 17 

Locaiion. ^Yheve paA'emeiits are nari'ow the trees must be 
placed close to the curb in order that their crowns mav have 
room in front of the buildings. They will be crowded at 
best. Where space permits it is best to plant Don't uiant 
inside the footway. There the trees are less curi>. 
subject to injury and shade the sidewall^ and the houses rather 
than the road. See Fig. 14. 

Footing or Growing Space. As explained on page 24, 
every tree planted should have at least 6 square feet of open 
earth above its roots. If the sidewalks and roadway are 
paved with concrete this is even more important than where 
bricks, or other jointed materials are used. On Give a tree 
narrow sidewalks the space may have to be """o™- 
limited to fi-o feet by 4 feet, but with that as a minimum 
strive for openings 3x8 feet, or better still, a continuous park- 
ing. Figs. 8, 14, 26, Plates I, II. 



THE TREE. 

Be sure to get healthy, well shaped trees. It is a waste of 
money and time to set the poor deformed things that nursery- 
men sometimes supply. Wild trees can be used, but they are 
less apt to withstand the shock of moving than those that 
Iiave been transplanted once or twice. Don't seek cheap 
trees ; get them from a responsible nurseryman. 

Size. It is often possible to set out trees as much as 12 
inches in diameter, but the cost increases much more rapidly 
than the size. As a rule the stems of the trees should be be- 
tween 2 inches and 3 inches in diameter, and about 12 feet 
tall. This serves pretty well the common desire for early 
results at a reasonable cost. 

Roots. Move a tree with as many roots as possible. It 
may grow if only the stubs of the main roots are saved ; it Avill 
do much better if the whole root work Avithin a radius of 2 
feet is taken; give especial care 1o the finer spnre the 
rootlets, they are the ones that do the feeding. ' """o***- 
Kever let them get dry ; a dry root is dead ! 

2 



18 



Shade Trees. 




Fig. 6. Young tree as 

received from the 

nursery. 






^E- 



^r 



Fig. 7. Same with 

top and roots 

pruned. 



Crown. Preserve the normal crown, or the form de- 
veloped in the nursery, if possible, if the root system has 
been much curtailed it will be necessary to cut back the crown 
to maintain a balance between roots and foliage, yet this 
balance is much better kept by saving roots than by sacrific- 
ing branches. (Figs. 6, 7, 8.) Grood trees rarely come from 
Expand tbe the bcau polcs that are often planted. The 
crown. lower brauclies of a street tree should be not less 

than 10 feet above the sidewalk. While it is small something 
less may be jjermitted, but sufficient headroom should always 
be allowed passers-by. If this is not done the tree is sure to 
be injured. Observe how the branches bend when the leaves 
are ivet wdth rain and give plenty of room for umbrellas. 
See Pruning, page 37. 

THE HOLE. 

Before a tree to be planted is brought on the ground have 
the hole mad-e ready for it. If the site is on "made'.' ground 
take out at least a cubic yard of the rubbish and provide as 
mucli good loam. Then prepare the planting liole, by dig- 
ging or bv filling as the case mav be, so that it shall be some- 
what larger than the root area, and about a foot deeper than 
the roots. On the bottom spread a layer of fine, mellow soil 



S.TEEET Trees. 19 

mixed with one-third its hulk of well rotted 

(not fresh) stable manure. Have the space SeVr"*' 

ahove this bed just deep enough to accommodate " *''''^' 

the roots and allow the tree to stand about 2 inches deeper 

than it did in the nursery — not more. 



PLANTING. 

If a choice is allowed always transplant a tree on a cloudy 
day; a bright sun quickly exhausts the stored up moisture. 
But whenever the tree arrives get it into the groimd without 
delay. Thoroughly wet the earth in the hole that has been 
prepared, set in the tree and spread out the roots so that they 
lie naturally and are not crossed. Cut off with a sharp knife 
all that are broken or badly bruised. A mutilated root in- 
vites decay. Then till in finely pulverized earth, work it 
under and around the roots by hand, and compact it firmly. 
Do not let any manure come in contact with the roots. If the 
earth is wetted down as it is put in it v/ill make a much better 
contact. Fill the hole to the ground level when well com- 
pacted, then rake over the surface and pulverize it to a depth 
of about an inch. Two points are very important : keep the 
tree vertical and be sure that all the roots are well embedded. 
It is possible to injure the roots by making the earth about 
them too hard, yet more trees are lost through i^,,,^,^ 
faulty root bedding than in any other way. *«*"'• ^o^^^et. 
Eemember that a tree feeds by its roots; to do that every 
smallest rootlet must be firmly in the soil. 

When planted tie the tree to a strongly set stake, or place 
the guard about it at once. 



20 



Shade Trees. 



WELL DEVELOPED HEAD. 
GOOD LEADER, MAIN 
BRANCHES FORMING 
WIDE, NOT CLOSE. 
ANGLES WITH STEM. 



STAKE 2i INCHES BY 
10 FEET DRIVEN 2 FEET 
IN GROUND. 



RUBBER COVERED WIRE, 
OR CANVAS, BINDER. 




TREE PRUNED AS 
ORDINARILY REQUIRED. 
IF ROOTS ARE FULL 
CROWN NEED BE LE5S 
CURTAILED. 



BASE OF PERMANENT 
CROWN 10 FEET 
ABOVE PAVEMENT. 



BED DUG OUT 18 INCHES 

DEEP. THEN FILLED TO 

LOWER ROOT LEVEL WITH 

MIXTURE OF ^ GOOD SOIL 

AND^ ROTTED MANURE. 



BASE OF TEMPORARY 
CROWN 7 FEET 
ABOVE PAVEMENT. 



MULCH OF 
PULVEBI2ED EARTH. 




PLENTY OF FIBROUS 
ROOTS. BROKEN 
ROOTS CUTOFF SMOOTH. 



RICH EARTH PACKED 
FIRMLY ALL ABOUT ROOTS. 



Fig. 8. Diagram— How to plant a street tree. 
It is Important to Observe Every Point Indicated in the Diagram. 



Street Trees. 21 



CARE OF TREES. 

Xo tree on a citv street can look ont for itself ; it must be 
taken care of. This involves protection against injury of 
every kind, provision for necessary nourishment, and, at 
times, some help to ward off insects or disease. 



GUARDS. 

The first needs of a newly planted street tree are a stake to 
keejj it upright, and a guard to protect it against horse-biting, 
wheel scraping and all mechanical injury. Young trees are 
best protected by devices which serve as well for support, as 
the ugly, but practical, box used in Washington, D. C. 
(Plate II. C.) Those that are established need only a shield 
against horses and accidents, or none at all if the police regu- 
lations are enforced. Various forms of guards _ ,. 

. -, Police regii- 

are shown in Plate IT. Any of these is good lation better 

r- n • 1 IT than me- 

hut unless it is stroneiy fixed m the ground the chanicai 

guards. 

young tree should be fastened to a stout stake 
as in Fig. 8. In binding a tree to a stake, or to a guard, 
the bark must be shielded against rubbing. For this purpose 
wire covered with rubber hose is much better than cords. 
Don't let a tree break loose from its guards. It will get be- 
yond the need of support in a year or two, but will always be 
subject to abrasion. As the tree grows see that its guard 
and fastenings do not cramp it. Keep the guard painted and 
in good repair. The necessity for constantly looking after 
tree oiiards shows how much the trees would suifer without 
them. (See Plate I.) 



22 Shade Tkees. 

PLATE II. 

Types of Tree Guards and Gratings. 

All but cut G from photographs by Dr. W. A. Murrill, of the New 
York Botanic Gardens. 

A. Tree Guard and Bench. London. 

B. Young Sycamore with Pole Support, Wire Guard and Grat- 
ing. Paris. The enlarged bases of the guards in cuts B. H. 
I., and the sheet iron on the guard in cut F, are to protect 
the trees from dogs. 

C. The Standard Guard used in Washington, D. C. This is 
strongly made of wood, is firmly fastened to four diagonal 
stakes driven into the gTound, and, by leather bands at the 
top, supports the tree as well as protects it. These guards 
are unsightly and harbor insects, but they are always re- 
moved after the tree is well established. 

D. A Simple Guard of Wire Netting. Washington, D. C. This, 
and all kinds of metal guards, are now being discarded and 
the older trees left to the protection afforded by stringent 
police regulations and systematic inspection. 

E. A Guard of Pine Poles. Berlin. Not so cheap here as in 
Germany and otherwise not desirable. 

P. Wire Guard with Sheet-Iron Base to protect the tree from 

dogs. Fraiikfort, a. m. 

G. A Neat Iron Guard but too Light to last Long. Trenton, N. 

J. Contrast small growing space with spaces shown in other 
pictures. 

H. Y'oung Tree with Wooden Support, Iron Guard and Grating. 

Berlin. 

I. Older Tree with Guard and Grating. Paris. Contrast large 

grating in concrete pavement with smaller grating in broken 
stone pavement, cut H. 




Plate II. See descriptions opposite. 



24 Shade Tbees. 

Gratings. Tn soiue cities the bases of trees are protected 
and their roots given air, by means of iron gratings set in 
openings in the pavement. Plate II. shoves a number of these. 
In exposed situations these gratings are valuable, but apart 
fro]n their considerable cost they mast be rai?3d frequently 
and the space cleaned out. It is well to avoid their use as 
far as possible. 

NOURISHMENT. 

More street trees sufl'er from starvation than from anything 
else. In many places food, water and air are all denied ; and 
the greater part of the harm is done by laying the pavement 
close to the tree. Don't plant a street tree unless it can have 
six square feet of open earth at its base. In Washington, 
D. C, the regulation openings are 3 feet by 8 feet, or 24 
square feet. (Plate II.) A generous space of earth about 
a tree is absolutely necessary for health. While a tree is 
young the soil in this opening should be stirred frequently 
Tree roots to admit air and control evaporation ; after it 
need air. bccouies of good sizc grass may be allowed to 

cover the opening although constant cultivation will stimulate 
growth. 

In summer if rain does not fall for several weeks the tree 
should have water, for pavement, sidewalk and house fronts 
become so heated that the evaporation from the leaves is 
greatly increased. Unless the water thus drawn off is re- 
placed the tree suffers. A thorough saturation of the soil 
every week or ten days is better than more frequent sprink- 
ling. A good plan is to build an earth dam about the tree, 
three or four feet from its base, or as near that as the pave- 
pienty of mout will permit, and fill the enclosed space 

water. with watcr, several times if necessary. When 

the water has all been absorbed, and the top soil is dry, break 
down the dam and spread the pulverized earth over the wetted 
area. That will retard evaporation. Be careful not to 
water so frequently that the earth becomes soggy and sour. 



Sttjeet Trees. 25 

Trees need food as iiiueli as animals. In the forest they 
get what thev require from the decaying leaves and other 
litter; along unpaved roads they nsiially are fertilized from 
the organic matter washed into the gutters, but on paved 
streets all this is gathered up and taken away. This de- 
ficiency can easily be supplied, howe^'er, by a little old stable 
manure spread over the open space in spring peea your 
and worked into the soil with a fork or rake, or *ree.s. 
it can be heaped about the tree o^-er winter and removed in 
the spring. If the exposed manure is objectionable a com- 
mercial fertilizer may be substituted. For light soils mix 
equal weights of nitrate of soda, acid phosphate, muriate of 
potash, and ground bone and aj^ply in the spring at the rate 
of from 1 to li/o pounds of the mixture to 100 square feet of 
exposed soil. This equals from iy_i to 2 ounces for a tree 
with a footing of 8 square feet. For heavy clay soils mix 
2 parts nitrate of soda, 3 parts acid phosphate, 1 part muriate 
of potash, 2 parts bone meal. Apply at the same rate as the 
above. In either case distribute the fertilizer evenly and 
mix it thoroughly with the soil. Be careful not to use too 
much else the tree roots may be burned. Where it is inad- 
visable to break the sod, or to work the soil, beneath a tree 
make holes with a crowbar about six inches deep and two 
or three feet apart and fill them with this mixture. 

The task of nourishing a tree properly is not so simple as 
these instructions seem to make it, but nothing more specific 
can be said without considering the natural soil and the kind 
of tree. The essential point is that trees need nourishment 
and need reasonable care. Thin foliage, slender branches, 
and dead tops (commonly called stag-head) are all signs of 
starvation and must be heeded or the whole tree will die. 



2(5 



Shade Trees. 




Fig. 9. Such exposure of roots is bad, but may be tolerated until a new 
tree can be established. 



INJURIES. 



All street trees are subject to injury of many kinds other 
than those against which ordinary guards are provided. 

It is the duty of every owner who occupies s]iace on the 
sidewalk to maintain a good tree, to co-operate with his neigh- 
bors, the Shade Tree Commission or other local authority, 
and with the public service corporations that also use the 
streets, to the end that injuries of every kind may be avoided 
or promptly remedied. 

The principle that shade trees have a direct bearing upon 
property values is well established in this State, and one who 
v„i„e suffers loss can recover far more than the wood 

of trees. value of a killed tree or the cost of a new one. 

JSTevertheless contests should be avoided, and in the follow- 
ing pages an effort is made to show how all interests can be 
harmonized as well as how various kinds of injuries should 
be treated. 



Street Tkees. 



27 



Construction and Building. 



Shade trees have no proper part in any construction work, 
whether of street, sidewalk or building. When thev stand 
near by provision must be made to secure them against in- 
jury, otherwise they are sure to be dauiaged. Most of the 
things to be looked after may be summarized as don'ts. 

Don't allow any guy wire or rope to be fas- 
tened to a tree. But if this cannot be avoided 
be sure that the tree is amply protected by wood blocks as 
shown in Fig. 11. A pretended guard of sacking as shown 
in Fig. 10 is of no value. 



Don'ts. 





10. A tree choked by a 
guy wire. 



Fh 



11. Guard a tree thus if it 
must anchor a guv. 



Don't allow a tree to be used as part of a scaifold ; it can 
always be avoided. 

Don't allow bricks, stone or any building material to be 
piled against a tree unless strong wooden guards are placed 
about it. See Fig. 12. 

Don't allow piles of sand, stone, etc., to stand long about 
the base of a tree; such material will rob the roots of air 
the same as a close paA'ement. See page 24. 

Don't allow a mortar bed where water saturated with lime 
can flow from it to the ground about a tree ; the roots cannot 
stand it. 



28 



Shade Tkees. 




Fig. 12. Every tree well guarded against injury while building goes 
on. Paris. Photo by Dr. W. A. Murrill. 



Salt. 



Salt in excess is fatal to tvee roots. Be careful if it is 
used to melt ice on the sidewalk, and don't allow brine from 
an ice cream tub to be emptied near a tree. 



Gas. 



Illuminating gas from defective mains is a common cause 
of injury to street trees. Otber gases, especially sulfurous 
acid, when discharged into the air in large quantity may 
damage or kill them, but this happens only near chemical 
works and under conditions not at all common. If a buried 
gas pipe is not pei'fectly tight the escaping gas poisons the 
soil about it and affects nearby trees more or less seriously in 
proportion to the quantity of gas discharged into the soil pene- 
trated by the roots. Thus, other things being equal, the 
nearer a tree is to a leak, the greater lhe danger that it will 



Street Trees. 29 

be killed and the quicker the poison will act. Conversely a 
small leak, or one at some distance from a tree, may indnce 
so slow an action that the real canso of the tree's failure 
cannot be determined. The activity of gas poison depends 
also upon the character of the soil, the material of which the 
road and sidewalk are made, the species and the vigor of 
the tree. For instance, clay soil will allow gas to escape 
from it less quickly than sand, but if the road surface above 
it is gas tight tree roots in either will have little chance. 

!N'ot infrequently an actual leak can be lo- Locatius 
iated by observing that trees and other vegeta- 
tion are affected with ^-ariable severity within a circle having 
a radius up to one hundred feet. The source of the trouble 
will be found near the center of the circle and near the tree 
that suffers most. A poison case may develop so rapidly 
from a large, sudden leak that se^^eral trees will be killed 
within a day or two. Ordinarily, however, leaks are small 
and the poison spreads slowly. Sometimes only a part of a 
single tree is affected. 

But it is often difficult to establish a case of signs of 
poison because most of the evidences may be ^"* vo^^on. 
produced by other causes. If, however, the leaves develop 
less size than usual, or wilt after they unfold — usually be- 
ginning at the ends of the branches — or if they droop sud- 
denly in mid-season, a gas case may be suspected. Later 
and surer sigTis are dark blue stains in the inner bark. These 
stains will often be foimd in the roots when they do not ap- 
pear in the body. Loosening of the bark usually follows 
death, whether gas or something else be the cause. One who 
is not expert should hesitate to declare a case of this kind. 
The odor of gas is the surest guide to its presence. If that, 
or a failing tree, indicates a leaky main drive a crowbar 
three feet into the ground as nearly as possible over the joint 
that may be faulty. Then withdraw it and put your nostrils 
to the hole. Don't try with a match for that may cause an 
ex]:)losion. If gas is present lose no time in having the 
leaky joint, or joints, exposed and made tight'. Where trees 
are endangered it is important to free the soil of poison at 



30 Shade Trees. 

once. Ordinarily all this will be done by employes of 
Gls^elm" ^^^*^ ^'^^ company if the case is reported directly 
•»«»?'• to headquarters, for any gas company wants to 

a^oid claims for damages on account of leaks, it also wants 
to stop the loss that leaks occasion. It is possible to make 
this positive statement because gas superintendents in this 
State have repeatedly sought advice of the Forest Commis- 
sion, or of Shade Tree Commissions, have followed the recom- 
mendations made, and in numerous cases have settled claims 
for damage on the basis of the opinion rendered. The Forest 
Commission is always willing to help adjust differences of 
this kind provided both parties wish it and agree to accept the 
forester's decision. 

How to ^^ ^ ^I'fs ^^s been poisoned by gas, but is not 

save a tree. killed wheu the leak is found and stopped, it 
may sometimes be saved by digging a trench about it, on the 
gas side at least, as deep as and including the gas main and 
from six to ten feet from the trunk, and leaving the trench 
open for at least a month. If rain does not fall plentifully 
water the earth about the tree roots. This will give the 
confined gas a chance to escape. Of course care must be 
taken that the tree is not so dug out that it will be overthrown, 
and thiu the earth from the trench is thrown away from, not 
towards, the tree. All this may be difficult in a crowded 
street, but is the only remedy. If the tree shows signs of 
reviving let the out-thro^^m soil be worked over several times 
and thoroughly aerated, or better carted away and replaced 
by fresh, then fortified by one-fifth its bulk of well rotted 
compost and the trench filled up. Stimulate the tree further 
by a top dressing spread within the trench line as advised on 
page 25. In some cases a severe pruning of the crown will 
aid recovery by reducing the strain on the root system. Un- 
less a tree is dry and has no signs of life in buds or stem don't 
conclude that it is dead until it has passed a summer after 
being affected. Xature is full of resources, and often seems 
to make light of serious injuries. On the other hand spring 
sometimes s'ives a semblance of life to a tree that is actuallv 



Street Teees. 31 

dead by developing winter buds into foliage that is apparently 
normal. 

When a tree is dead remove it, and before ]3lanting another 
in its place change the soil or freshen it as directed above. 




Fig. 13. How lack of system gives a poor effect. Trees of all kinds, 
shapes and conditions. Contrast Figs. 1 and 4. 



Electric Wires. 



Contrary to the common belief electric v^ires Rarely 
are rarely directly harmful to trees. They are 'larnifni. 
objectionable chiefly because the workmen who look after 
them are careless or indifferent and do unnecessary damage. 
The current in a telephone wire is too weak to be injurious 
under any circumstances, while a lighting wire Aitemat- 
carrying an alternating current will injure the rect"eur-'" 
living tissue of a tree only when wet weather ^ents. 
and the loss of insulation make possible a close contact. Most 
of the injury done to trees comes when a high tension direct 
current escapes, as from a trolley feed wire, and burns the 
tree at the point of contact or is grounded through its trunk. 



32 Shade Trees. 

In the latter case a tree may be killed as by a lightning bolt. 
But injuries of this kind are too rare to require special con- 
sideration. Moreover, the management of no electric com- 
pany will long neglect a contact that means a loss of energy 
in its lines. 

grmmci ^^ will be admitted that overhead wires are 

practicable objcctionable in any organized community and 
where sliould be put Underground wherever it is prac- 

ticable. Let every effort be made to extend the territory 
within which all wires must be carried out of sight, but at 
the same time let the facts as they affect most tree interests 
be not forgotten. These are that electric service is indis- 
pensable, that the electric companies have certain defined, 
rights in many streets, that private, municipal and corporate 
interests are more often served by agreement and compromise 
How to har- than by contest. And it is always easier to ad- 
!^dV"l^rins* i^^st a matter of this kind before a franchise is 
interests. granted, or before Vv^ork is begun, than after an 

installation is in place. The following suggestions may help 
to resolve various difficulties in connection with shade trees: 

1. If wires are to be extended to a street not previously 
served, seek by agreement to have the poles set behind the 
houses rather than in front. This is often difficult, as where 

the street lights are on a high tension circuit 
of build- while the houses are served from a low tension, 

or it may be impracticable for other reasons. 
jSTevertheless it cair bo accomplished in some cases, especially 
if the property owners are reasonable with respeci to allowing 
linemen free access to the poles, and provision is made for 
crossing intersecting streets. 

2. If wir(\s are to be run on a shaded street where they 
have not been before, try to ha^"e the itoles set on one side or 
the other of the tree line, preferably next the curb. (See 
Fig. 14.) 



Steeet Tkees. 



33 




Fig. 14. Trees on curb, A, must compete with electric wires. Those 

inside walk, B, have head-room. Note fine row, ( ■, protected 

from street by sidewalk. 



above or 

around 

trees. 



3. If lighting wires must be run with a line of trees con- 
sider whether they shall be carried on high poles over the 
trees, on crossarras projecting into the street, or through the 
bodies of the trees. The chief objection to the first plan, 
next to its unsightliness, is that the growth of the trees will 
almost surely bring the upper shoots into contact with the 
wires and thereby cause them to be broken and wiring,- 
the tree croAvns distorted. At the same time 
the wires will be disturbed, and the current per- 
haps grounded. This is rarely a good plan. Carrying wires 
on projecting crossarms is objectionable because it interferes 
with the freedo7n of the roadway, and looks badly. The de- 
vice should be resorted to only in exceptional cases. As a 
rule it W'ill be found most practical and most „,. . 
satisfactory to carry wires through the bodies through 

^ ./ ~ trees, 

of trees and quite low down. They must be 
insulated, of course, but when that is done properly the trees 
will not be injured and the wires themselves will be less dis- 
turbed bv the normal tree movements. Trolley feed wires 



34 



Sua OK Tkkks. 



sluniM alwavs l>o pro|Hn-l_v insulaUHi and (.-ari-iod as low down 
as i.< practicablo. 

4. T(dopliouo wiros should ahvavs Ik oarriod ihrouiih the 
AViros In lowov jHU't ious ol" t ivos. aud wliou iliovo avo sov- 

*■"*•'''"• oral bo uuitod in a cable. (^See Fig. lo.") Ir is 

not |M'aetieahli> [o oaMo high tension wires. 




Fig. 15. CMd trees (.\ IX K. on a new o-radt? and with cabled wires throiigli 
their oi-owns. New trees shonUi be phuited at X. X, X, and 

when they are grown the oUl ones removeii. 

o. it Tv«.vs are lo be planred in a street where the only 
available room is already oeenpied bv wires, that is a street 
with little space between the curbs and bnihiing lines, there 
are jnst three conrses open: one. to indnee the electric com- 
pany to remove the wires before the trees are set: tiro, to 
gx^t an agTcement that they will be removed or raised at a 
fixed time in the futnre, or when the tives shall have groAvn 
so that tree shoots and wires interfeiv : three, 
to |\lant low growing trees and by prnning keep 
them below the wires. The last is often a good 
plan, as big trees are ont of place in a narrow street. 



Plant low 
trees. 



Steket Trees. 35 

"With respect to the damage done by linemen 
there is now less ground for complaint than do^^by 
there formerlj was. N'evertheless such men ""^™^"- 
will bear watching, and should be given to understand that 
they will be held responsible for any injury. There is ample 
law and precedent in the State to prevent injury in this way, 
as well as to secure redress if the property 
owner will trouble himself to protest and, if enough 
necessary, to prosecute his claim. It will not *o^^a>-d aii 
often be needful to go further than to make a 
formal complaint or claim; corporations dislike litigation 
and will satisfy any just demand. Two points only need be 
obsserved: 1. Forbid absolutely the use of climbing spurs; 
they are unnecessary in tree work, and every time they break 
the bark give disease germs a chance to enter. And forbid a 
workman to go into a tree, even by a ladder, with his spurs 
on; they will damage the bark on the branches. 2. Eequire 
the man in charge of the work strictly to observe the rules 
of the isTational Electric Light Association. These rules have 
been adopted by most of the telephone, telegraph and lighting 
companies, and in themselves prove that the officials are ready 
to do their share to avoid trouble. The most important of 
the rules are : * 

"11. Wires shall be struug- on the side of the street most free from 
trees." 

"66. Guy wires shall not be attached to trees wjthout the permission 
of the owner or other proper authority." 

"68. Tree trunks and limbs shall always be protected from injury by 
the use of tree blocks between the tree and the wire attached thereto." 

"8.3. Line wires shall not be supported upon trees." 

"89. It is essential for the safe and uninterrupted ^Virlng 
operation of lines that they be free from possibility of """ ^** 
grounding on trees. It is therefore important that tree branches inter- 
fering, or likely to interfere, with the lines should be cut away. Such 
trimming must be done with care and judgment, and under the super- 
vision of the superintendent, line foreman, or other responsible person." 

*From report of Committee on Overhead Line Extension. New York, 
June 2d, 1911. 



3G 



Shade Teees. 



"90. Before any trimming is done the consent of tlie owner of the tree 
should be obtained.* Opposition to tree trimming may sometimes be over- 
come by offering to employ a professional gardener for this purpose. If 
consent to trim trees cannot be obtained, and the interfering branches 
cannot be avoided by the use of longer crossarms, or by offsetting the 
standard crossanns, tree wire shall be used." 

"91. The stubs of branches shall always be painted for their protection 
and to make them less noticeable." 

"94. Where tree wire is used, if there is danger of limbs or large 
branches chafing the insulation, it shall be protected by means of wooden 
abrasion moulding." 




Fig 16. Abrasion moulding - used to protect trees and 

wires. (Courtesy of National Electric 

Light Assn.) 



Insects, Diseases. 

These subjects are presented fully by Dr. Smith aud Dr. 
Cook in their accompanying papers. 



Abrasions, Hoese Bites. 

A tree whose bark is broken is hastened towards an early 
death. Prevent such injuries by guards and by police regu- 
lations. Be particular about the lawn mower. Half our 
shade trees are repeatedly bumped and permanently injured 
through wounds made at their bases. (See page 54.) If a 
tree is so damaged have it treated promptly as directed on 
page 44 and Fig. 20. 



♦Where there is a Shade Tree Commission it has authority above the owner 
and will help to adjust differences. 



Steeet Teees. 



37 



PRUNING. 

Under normal conditions a tree needs little or no pruning 
but, at least until it gets ragged from age, is best left to de- 
velop its natural form. Shade trees, however, frequently re- 
quire pruning to adapt them to their surroundings and to 
maintain a healthy growth. A tree does not de^^elop at ran- 
dom but after its kind and with reference to the stimulants 
and checks that are brought to bear. One of the most im- 
portant of these influences is light. Light has a direct in- 
liuence upon the form and health of a tree. 
The strongest growth of a tree's branches is 
made toward the brightest light. The parts of a tree which 
for any reason are shut oif from the light weaken and sooner 
or later die. 



Light. 




Fig. 17. Norway maple with character- Fig 18. Norway maple after an interior 



istic dense crown. The foliage devel- 
oped on tills drains the roots in 
dry weather and weak- 
ens the tree. 



pruning. This modifies the shape of 
the tree in no way while reduc- 
ing its leaf ai'ea and thereby 
increasing its vigor. 

Pruning for Vigor. 



38 Shade Teees. 

Street trees must be made to develop so that they will not 
interfere with traffic, and in such a way as to make the best 
use of existing light conditions. This is accomplished by 
pruning. Subject to differences necessitated by abnormal 
conditions, a tree which has been skillfully pruned for a 
number of years will approximate the following description : 

1. There will be a primary frame consisting of from one 
to three axillary branches, the number depending upon the 
species. A tulip or pin oak will have a single axis, while an 
elm or maple will have two or more co-ordinate members. 
A properly 2. Grouped about the primarv frame will be 

formed -^ . . ^ 

tree. several less imposing branches so arranged as 

to form a symmetrical frame work and characteristic of the 
species. 

3. Each branch and branchlet will be free from physical 
contact with its neighbors. 

Unless the tree has had proper care from the time it was 
planted it will fall far short of this ideal, and quite heroic 
methods may be necessary to overcome the neglect of years. 
The commoner rules for pruning may be summarized as fol- 
lows : 

At the Tijie a Tree is Plakted. 

1. The object of pruning at planting is to make the tree 
live. If it is necessary to sacrifice form to secure this re- 
sult, do so. After a tree is thoroughly established its growth 
to the proper form can always be accomplished. 
Pruning -* ^^ ^hc roots are intact it is not necessary 

for life. ^y prune the crovra.. It is seldom, however, 

that such is the case, and the removal of from twenty-five to 
fifty per cent, of such branches as are not needed in the 
shaping of the crown will be a wise precaution to counteract 
root injury. 

3. If any of the roots are broken remove the injured parts 
by making a clean cut. Balance this cutting by removing a 
slightly greater relative proportion of the crown. Sometimes 
it will be necessary to remove practically the entire branch 
system to obtain a proper balance. (See Figs. 6, 7 and 8.) 



Street Teees. 39 

WiiEX A Young Tree is Fully Established. 

1. Select the primary frame according to the growth habit 
of the species in hand. 

2. Select several secondary branches which pruning- 
either do, or can be made to, conform with the ***'' **"""'' 
primary frame in harmonizing the shape of the tree. 

3. Remove any of the larger branches which do not con- 
form to the general character framework. 

4. If the primary frame is vigorons enongh to maintain its 
domination over the secondary development, simply remove 
the smaller interior interfering branches. 

5. Curtail any of the main branches which threaten to as- 
sume midue propo]-tions by removing a part of their terminal 
gro^\'th. 

When a Tbee is Well Developed, but Unpbuned. 

Most trees of this class will carry a considerable burden of 
dead wood in their interiors, and a large amount of half sup- 
pressed and vigor-lacking growth throughout the mass of 
branches. There is usually considerable irregularity in the 
form of the tree due to the greater vigor in some branches 
than in others. (See Fig. 17.) 

1. Remove all dead wood. pruning- 

2. Select from the most vigorous branches the ***'' vigor. 
character framework as outlined above. 

3. Remove all branches large or small which do not fit in 
with the scheme of form development decided upon. 

•i. If the primary frame does not distinctly dominate, 
curtail the secondary development by clipping the terminals. 

5. If necessary to cut back any large branch by a con- 
siderable amount without entirely removing it, leave a vig- 
orous small branch near the point where the cut is made to 
act as a ''sap lifter'' and thus insure the life of the branch 
which has been shortened. 

G. Establish an individuality in each branch by removing 
from it such parts as would bring it in contact with its neigh- 
bors, or which grow contrary to the characteristic habit of the 
species. 

7. Remove internal decay as indicaled under "Treatment 
of Cavities," page 45. 



40 



Shade Teees. 



When a Teee is Neglected and Decadent. 

Old Tintrimmed trees always contain broken branches and 
mncli dead wood, and frequently possess certain branches 
which have grown disproportionately. This irregular growth 
and mutilation often develops a picturesque appearance which 
should be retained unless there is some outweighing reason 
for altering it. Under no circumstances allow a tree to be 
"topped," that is, reduced to a post with branch 

"Head in" |^ , -r^- ^ rs tt i i 

but don't stubs at the top. Jbig. 19. Under any but ex- 

ceptional conditions the practice is butchery. 
Better take the tree away and plant a new one. "Heading 
in" is another matter, and if carefully done may cause 
a decadent tree to recover its form as well as its vigor. 




Fig. 19. Butchered maples. Not necessary to escape the wires and in 

no way justified. The winter aspect of a tree is almost as 

important as its summer aspect. 



Street Trees. 41 

An old tree if moderately sound will stand, and be thankful 
for, any reasonable treatment of its crown. In a case of this 
kind observe the following: 

1. liemove all dead wood. 

2. If all the large branches must be cut back make at least 
two operations, a year or more apart. 

3. Make the cuts so that the stubs of the "headed in" 
branches will roughly conform to the desired shape of the 
crowii to be. 

4. Be sure that a small "sap lifter" is left on each short- 
ened branch near the place where the cut is made. 

5. Treat all decay as directed under "Treatment of 
Cavities," page 45. 

How TO PKUiVE. 

In removing a branch it is important to make the cut close 
to the trunk, or remaining branch, and to take such precau- 
tions as will insure a clean wound without injuring the sur- 
rounding bark. An ordinary hand saw or a pruning saw is 
generally used. Unless the branch is quite small saw under- 
neath first and finish from above. This is to prevent the 
splitting down of the branch, or breaking the surrounding 
bark. In removing any sizable limb, make first a half cut 
from the under side and about a foot from the trunk; then 
sever the limb entirely by a cut a few inches further out. 
(Fig. 20 B.) The object of the undercut is to prevent the in- 
evitable split from running back to the base of Avoid 
the branch. Finally remove the stub close to sp"*"^^. 
the trunk. If a limb is very large and heavy, and there are 
other branches beneath, support it from above by means of 
ropes in order that it may not fall and do damage. Be sure 
to make the final cut as close to the tree trunk 
as possible, since a large wound there Avill close 
in a more satisfactory manner than a smaller one at the end 
of a short stub. And be especially careful that as the severed 
limb finally falls the bark next its underside is not torn from 
the tree. 



PREVENT A SPLIT OR 
MEND A SPLIT BY CHAIN 
& BOLTS. NOT BY A BAND. 
SEE I . 



STUB 
TOO LON€ 
FOR HEAL- 
THY . 
HEALING 
AND DECAT 
WORKS 
INWARD. 



A PRUNING 
WOUND MADE 
AS B OR C 
HEALING PER- 
FECTLY. 



A WOUND FILLED 
UNNECESSARILY, 
TREATMENT AS 
E OR K WOULD 
BE BETTER. 



NEVER MEND A 
SPLIT WITH A 
BAND. THE TREE 
WILL SOON BE 
CHOKED, SEEA&D. 




A LARGE CAVITY 
PROPERLY FILLED 
WITH CONCRETE. 



Fig. 20. Diagram —How to doctor a tree. 



Steeet Trees. 43 



Suggestions. 



Ever- 



Do not prune evergreens, except hedges, un- 
less the severed member is wanted out of the greens. 
way. Evergreens do not sprout from cuts as do most de- 
ciduous trees. 

Pruning may be done at the most convenient Tpi,,,^ ^^ 
time unless the wound bleeds. As this is most p^-""*- 
likely to occur in spring that season is the least advisable. 
Fall or winter is usually best, for then the sap is least active 
and the leaves do not obscure the tree framework. 

Do not remove a live limb unless it interferes with a better 
one or otherwise fails to meet the form and health require- 
ments of the tree. 

Interior pruning is often necessary in the maples, bass- 
wood, and similar dense-crowned trees, because the foliage 
develops beyond the power of the roots to satisfy it with 
water. A treatment similar to that ordinarily Excess of 
given fruit trees is advised. (See Figs. 17 *«"«^'^- 
and 18.) 

The suckers or long shoots from adventitious buds, often 
observed on elms, give them a peculiar beauty not found in 
other common shade trees. Spare these instead of removing 
them as is often done. 

r>o not trust your tree work to the first man who comes 
along, but seek a reputable worker. Iso chestnut tree can be 
cured of the blight; a wound badly filled or 



Tree 



unnecessarily filled would be better left open Fakirs— 
(Plate III) ; and a tree that is sprayed care- 
lessly or with wrong material Avill be benefited as much as, 
and no more than, one that is butchered under a pretence of 
being pruned. 

Tree owners are warned against men without credentials, 
and those who have work of this kind to do are advised to 
seek assistance from the local shade tree commission, or, if 
help cannot be secured in that way, to apply to the Forest 
Commission, to the State Entomologist or to the State Plant 
Pathologist. 



44 



Shade Trees. 



CARE OF WOUNDS. 



i^^^ \ 


^1 


M^^^^^^m^ > 




h^M 


frn^ 




^^^^F/f j^H 


■■S' > 




^^^^^K^i A|^H 


■r ' 



Fig. 21. Four branch wounds with good cal- 
luses but each showing a cavity, the 
result of long stubs and lack of 
treatment to prevent decay. 
See Fig. 22. 



Every break in the 
bark of a tree should be 
treated with an anti- 
septic to prevent the en- 
trance of decay. But 
this rule is commonly 
ignored in so far as 
clean cut wounds, not 
over two inches in di- 
ameter, made in the live 
wood of a healthy tree, 
are concerned. But 
every pruning wound of 
larger size must be 
treated else decay may 
set in before it can heal 
over. (Figs. 21 and 22.) 
The treatment consists simply in painting the exposed 
wood with coal tar, creosote, or lead paint. The first is usu- 
ally preferred. Thin the tar by heating it if 
necessary and apply with a brush, being care- 
ful not to cover the cambium, or tissue between the wood and 
bark. Give two good coats and repeat every year or two until 
the wound is completely healed. 

Wounds due to mechan- 
ical abrasion or animal 
g-nawing should have all 
the injured wood and bark 
removed with a knife or 
gouge and then be treated 
as directed above. (See 
Fig. 20.) If the bark is 
merely scraped but not 
broken through, let it alone ^ig- 22. A group of branch .vounas 

~ . periectlv healed, no nlhng needed 

and see that it "does not as stubs were cut short and 

happen again." ''""see fT- ^r"^" 



Tar all 
woiindis 




Steeet Teees. 45 



TREATMENT OF CAVITIES. 

1. Kemove as mueh of the decayed ^rood as the location of 
the ca^■ity aud the condition of the tree seems to -warrant ; 
aim to ex]Dose a smooth snrface of sound Avood at all points. 

2. Sterilize the surface by a brush application of copper 
sulphate or creosote. 

3. Give the ca^dty at least three coats of coal tar, avoiding 
covering the cambium. 

4. If the cavity is of such shape that it will catch and 
retain water, or if it is so large that the tree is weakened 
thereby, fill it as directed below. 

5. If the cavity does not fall in either of the above classes 
it is best to allow the natural gro-\A'th of wood to gradually 
co\'er oA'er the defect. 



46 Shade Tkees. 



PLATE III. 
Tree Wounds Healing Without, and in Spite of, Filling. 

A. A bad scar on a fine elm healing perfectly without cement. 

B. New growth on a wounded elm which has forced out a cement filling. 

C. New growth closing another wound on the same tree and confining 

some of the cement. 

D. Strong new growth closing a bad scar that would have been better 

left without brick or cement. 

E. A fine callus closing a bad wound on a hemlock that has had no 

treatment. The decayed wound in center should be removed 
and the sound core tarred. 




Plate III. See opposite page. 



48 Shade Tubes. 

A word of warning must be given against the too free use 
of cement or concrete in treating trees. The material un- 
doubtedly has value in spite of a lack of elasticity that almost 
_ . inevitably prevents a fillinc; from beinff water 

Don't use • i • *" 

cement too tight. Or causcs it to crack and fall out of place. 

freely. ^ 

It may always be used where a tree needs me- 
chanical support, often where a cavity is unsightly, and some- 
times to keep out rain. Under other circumstances it usually 
is best to clean and treat antiseptically a cavity, certainly a 
superficial or shallow wound, and leave the rest to ISTature. 
In many cases a filling secretes rather than excludes mois- 
ture, thereby inducing decay, and unless it is very carefully 
made may interfere with the normal processes of repair. 
(See Plate III.) 

Where a cement filling must be made a few rules will 
serve to guide: 

1. Prepare the cavity as above and in addition remove 
the bark around its edge for about half an inch. This is 
to expose active cells in the cambium from which the healing 
callus may develop. 

2. Fill the cavity flush with the wood at the edge of the 
opening but do not lap over. If desirable the cement may be 
sculptured to resemble bark. 

3. A small cavity may be filled with pure cement. For 
large ones use a concrete consisting of one part cement to 
Cement ^^^'^ parts of saud and reinforced with stone, 
or concrete, brick Or irou. Covcr the exposed face with 
an inch of pure cement. Spikes driven into the wood inside 
the cavity will help to hold the filling in place. 

Another method is to cover the cavity with sheet zinc, 
carefully fitted and securely nailed to the exposed wood at 
Zinc its Gdge, and fill in concrete behind it. The 

facing. concrete should be liquid enough readily to 

adapt itself to the interior of the cavity. This is a simple 
and very satisfactory way to get the filling in place and to 
keep it there. Qf course the zinc must be first fastened at 



Street Tkees. 49 

the bottom and the concrete poured in from above. The 
zinc and the edges of the wound should be painted or tarred 
to render them less conspicuous. 



BRACES FOR CROTCHES. 

Acute angled crotches in trees of large size often split. 
To prevent this, or to repair a break, let iron braces be put 
in of size sufficient to withstand the strain. See Fig. 20. 
Do not let bands be used, many trees have Don't use 
been ruined by them. If the weight of limbs bands. 
is not very heavy a solid rod with screw threads on both 
ends can be used. Ordinarily, however, it is best to use hook 
bolts and a chain, or eye bolt, so that there may be some move- 
ment when the wind blows. Whether a single rod or a com- 
bination is used let a neat hole be bored entirely through each 
limb and as high above the crotch as is prac- 
ticable. If a rod is used these holes must be in ^/ chains. 
line, if a chain or eye bolt it does not matter. 
On the outer side of each hole countersink a seat for a washer 
at least 4 inches in diameter and for the nut. When the 
brace is in pJace make the whole taut by screwing up the nuts. 
If the tree has been split and the gap cannot be closed by the 
power of the screws rig a tackle higher up. Let the hook ends 
of the bolts project several inches so that they will not be 
buried as the tree grows, but see that the washer, nut and 
end of bolt are left so that they will be overgrown. 



WHAT TO DO WITH OLD TREES. 

j^othing that has been said about the choice of trees should 
be construed as a recommendation to remove a poor tree be- 
fore it can be replaced by a better one. A ragged old silver 
maple is often better than none. When systematic tree 
planting is decided upon accommodare the plan to existing 
trees and provide for a gradual replacement of undesirables. 

4 



50 Shade Trees. 

In the meantime fix np the latter and help 

Old trees , , ,. - , 

better than them to Keep alive : cut out all broken and 
dead branches, , heal the wounds and open the 
paveme]it so that the roots may have air. If necessary 
curtail the cro"WTis gradually so that new trees adjoining 
shall not he hampered in their development. If a tree is 
very bad don't waste time and effort but replace it at once. 





Fig. 23. Trees saved by mounding and raising curb when road was lowered. 
Note step in curb at A. Base of tree B is 30 inches above the gutter. 

Where a change of grade has left a tree above the common 
]e^'el don't leave it to be kicked and battered by every passer- 
by, but cover the roots with a few inches of earth and provide 
some means to keep it there. (Fig. 15.) A slight change 
in a sidewalk may be fully justified by the necessity of 
saving a valued old tree. If a new grade requires a fill 
about a tree don't pile on two or three feet of earth at once, 
but build a well of brick or stone at least 3 feet greater in 
diameter than the tree stem. (Fig. 24.) Let that fill up 
gradually and occasionally break the bark on the tree, just 
below the soil level, to encourage the growth of new roots. 



Steeet Trees. 



51 




Fig. 24. A " Well" constructed about an elm tree when grade 
was raised. Photo by \Vm. Solotarofli 



CO-OPERATION. 

In few lines of civic work is co-operation so essential as 
in the care of shade trees. The fact that one individual 
ordinarily owns and controls but a fraction of the property 
in a block makes it necessary for each owner to work with, 
and not indepeiidently of, his neighbors. In almost every 
community the best results will be secured through a Shade 
Tree Commission, or a Park Board having similar authority. 




Fig. 25. Street grade raised two feet without changing sidewalk or 
injuring trees. Practicable only on a side street. 



52 Shade Trees. 



SHADE TREE COMMISSION. 



Where a community interest in shade trees has been 
awakened the best way to get things done is to organize a 
shade tree commission. The State laws give ample powers 
to such bodies and one properly supported by local ordi- 
nances and reasonable aj)propriations will soon change the 
sylvic aspect of a municipality. The only objection to the 
laAvs as they stand that is of importance concerns itself with 
the unusual powers granted a Shade Tree Commission. The 
answer is that in practice the laws have worked no injury 
or injustice but have enabled several communities to care 
for their trees systematically and effectively. 

An individual may do the right things for the trees in 

front of his property and the community get the benefit, but 

ordinarily his interest is spasmodic and apt to 

iiais not be ineffective. He neglects to have his trees 

effective* 

fed, or doctored, or trimmed, or he employs a 
butcher who spoils them. A shade tree commission can pre- 
vent abuses and require symmetrical planting, can doctor, 
prune and spray, can make terms with the gas company and 
electric company and save the owner all trouble. Some 
property owners do not want to give over to a public body 
the care of trees which they have planted and nurtured. 
The position, though understandable, is unreasonable in a 
day when utilities and conveniences are developed for the 
advantage of the public. As well might each property owner 
insist on being allowed to do as he pleased resj^ecting side- 
walks, curbing, sewers. If every owner must dedicate a 
part of his property to the public for these purposes, he can 
quite as reasonably yield the care of liis shade trees that 
his neighbors as well as himself may be lienefited. An active 
Shade Tree Commission can do much good also by anticipat- 
pian for ^^^S ii^^nicipal improvements and harmonizing 

the future. various iutcrcsts. Where streets are repaved 
or grades changed an agreement with the engineers will save 
many an old tree from destruction. In not a few instances 
in this State has the want of co-operation, or co-ordination 
of duties and interests, deprived a town of trees that cannot 
be replaced. In new work the same unity is quite as neces- 



Lawn Trees. 53 

saiy. Large open spaces about street trees, for instance, 

can be made onlv with the consent of those who regnlate the 

])avements. 

Shade Tree Federation. 

The shade tree commission idea has progressed so far in 
Xew Jersey that an organization composed entirely of men 
and women actively interested in shade trees has been 
formed, it is in no sense a popular body, but devotes itself 
to ]3roblems that concern the various communities and their 
shade trees. In general it aims to be a sort of clearing 
house through which the experiences and needs of each com- 
munity or Shade Tree Commission can be made to serve all 
their fellows. 

Lawn Trees. 

The variety of lawn trees that may be grown in this State 
is almost unlimited. And here evergreens are quite as valu- 
able as deciduous trees. For the main features of any plant- 
ing plan the same species recommended for street planting 
will be found most satisfactory ; for contrasts, for pure orna- 
ment, for windbreaks, many other kinds are Many 
available. Individual taste will govern in this JEtossibie. 
and there is no objection to trying novelties. There are 
many native trees, however, that are rarely seen but which 
well deserve place. Serviceberry, dogwood, several birches, 
various magnolias, red bud, silverbell, sourwood, yellow 
wood, mountain ash, hawthorn, larch, cypress, arborvitse, 
hemlock, are all suitable, especially for sheltered situations. 
Many nurserymen are now prepared to furnish well grown 
trees and will guarantee them to live. Thus it is quite pos- 
sible to give an air of age to a new place within a very few 
years. Of course the cost of large trees is considerable. 

Trees on a lawn should be planted and cared for the same 
as street trees, though they will ordinarily need no guards 
and may easily grow much more rapidly. For 

, " "^ 1,^ . -, ," Must be fed. 

several years alter a tree is planted, no matter 
what its size, grass should not be allowed to grow about its 
base, but the ground kept open and frequently cultivated and 
watered. After the tree is fully established a turf may be 
allowed to form, but it will still need to be fertilized because 



54 



Shade Teees. 



its natiiraJ food, the fallen leaves, dead grass, etc., will have 
been removed. Open earth at the base of everj^ tree is recom- 
mended because, apart from all questions of nourishment, 
the bare circle acts as a guard against injury by lawn mowers, 
etc. 










Fig. 26. Ti'ee A stands in the gutter. Tree B in the curb line, Tree C 
is partly on the sidewalk. No harm done. 

It is well to observe several points about the (jualities and 
behavior of trees. Those which give a dense shade are usu- 
ally shade-enduring or tolerant ; they carry their own lower 
branches for a long while but kill or stunt trees, shrubs or 
g^gjj^ grasses that are intolerant or light-requiring. 

endurance. Q-^^ ^];^jg accouut grass docs uot gTow wcU uudcr 
a beech or spruce but may under oak or pine. Sugar maple 
will do fairly well in the shade of elm, but elm is hampered 
by sugar maple. Trees grow tall and slender when crowded, 
much broader when they have j)lenty of room. 

All trees do best in good soil, but some, as most of the 
pines, require it loose and well drained. Others like elm, 
ash and pin oak favor moist locations. 



Seashore Trees. 



00 



Evergreens, especially spruce, balsam, cedar, arborvitie, 
make tlie best windbreaks and permanent shade, but they 
should not be planted close to the house for they -vvi^d- 
cut off the sunlight in winter when it is wanted, breaks. 
Thin foliaged trees like elm, oak, sycamore, ash, are best in 
such places. 

Seashore Trees. 

Whether on streets or lawns, trees planted near the sea are 
subject to two great handicaps not commonly found else- 
where, namely, strong, constant winds and sterile soil. 
Close to the beach salt spray often works injury. These 
conditions make it imperative to plant only the hardiest 
species, though if great care is taken to prepare large beds of 
good earth sheltered lawns may enjoy a comparatively great 
variety. Especial pains must be taken to anchor every 
planted tree against the wind, for the breezes shteia from 
of summer are as nothing compared with the winds. 
storms of winter which it must withstand. In any case 
many trees will be permanently inclined or distorted as are 
those that a'row wild. 




Fig. 27. A well shaded lawn made from native forest near the sea. 



56 Shade Tkees. 

On lawns the native pines, oaks, cedar and holly should be 
encouraged. Though of slow growth under natural condi- 
tions cultivation and care will stimulate them. The mari- 
time pine {Pinus pinaster) of Europe is worth trying in 
exposed situations. Spruces and firs need protection. 

For street planting it will be best to try few experiments, 
but use the trees that are proven hard}^ and give them every 
Plant only carc. The species most likely to thrive are 

approved -i i • i - 

speoies. sycamore, ailanthus, pm oak, scarlet oak, red 

oak, chestnut oak, hackberry, honey locust, red maple. Pop- 
lars and silver maple will be very short lived. iSTorway 
maple is apt to burn by reflected heat. 

It is unfortunate that so little systematic or careful tree 
planting has been done in our seaside communities, A little 
active interest, and time of course, would transform their 
bare, sunny streets to as^enues of shade. 



Specific Characters of the Most Available Trees 
for Planting. 

AILANTHUS. 

A tree {Ailanthus glandulosus, Desf.,), imported from 
Asia, of luxuriant habit and ornamental appearance. It 
grows with remarkable rapidity in almost any kind of soil 
and makes a valuable tree for wide avenues. It is not well 
adapted to narrow streets. The tree is objected to on ac- 
count of the litter produced by its leaves and abundant fruit, 
its early defoliation, and especially the ofi^ensive odor of the 
male flowers. This last, however, is easily avoided by plant- 
ing only pistillate trees, since male and female flowers are 
often found on se]:»arate individuals. The tree is remarkably 
free from disease and insect pests and is well thought of in 
Paris, where it has been largely planted. It is a favorite in 
several cities in this country also, notwithstanding the error 
made by planting staminate trees in some cases. 



Most Available Trees foe Plaktixg. 



ASH. 

Of all the ashes, the white ash (Fraxinus Americana, L.) 
has the most desirable qualities as a shade tree. It requires 
a rich soil and does best in the presence of considerable mois- 
ture. Under favorable conditions it grows fairly rapidly 
and attains a good size with a moderately broad, open crown 
and thin foliage. It makes a desirable tree where a moderate 
shade is wanted in summer and much sunlight in winter. 
The tree has few enemies and is little subject to disease. 
The chief objection to it as a shade tree is that the leaves 
cojne late in the ST)ring and fall very early. The European 
ash is less desirable than this. Green ash (F. 'pennsylvanica, 
var. lanceolata, Sarg.) is a comparatively small tree but 
hardier than white ash. It is planted largely in the West 
and should have a place here on narrow streets and where 
onlv a moderate shade is wanted. 



BASSWOOD OR LINDEN. 

The most important species is Tilia Americana, L., a beau- 
tifid, large tree with compact cro^n, broad lustrous leaves, 
and a curious winged fruit. This is an admirable tree for 
avenues and streets of moderate width where sun glare is not 
excessive. On closely paved streets, and near brick or stone 
buildings, the tree suffers seriously from sunburn. Bass- 
wood requires good soil and considerable care. AVhere that 
can be given its beautiful foliage and fragrant flowers justify 
its planting. Under other conditions it shoidd not be at- 
tempted. The European linden is apparently less able to 
withstand the trying conditions of city streets than the na- 
tive species. 

BEECH. 

This tree has no value for street planting, but either the 
native species {Fagus Americana, Sweet) or the European 
(F. sylvatica, L.) makes a beautiful lawn tree. They require 



58 



Shade Trees. 



rich, well drained soil and grow rather slowly. Under free 
conditions the tree is quite short but develops a broad heavy 
crown which casts a dense shade. There are many orna- 
mental forms of the European species — as purple-leaved, cut- 
leaved and drooping. Many of the leaves adhere to the 
branches through the winter, a habit that some people con- 
sider a fault, others like the constant rustle of the dried 
leaves, as well as the appearance of the tree when most others 
are bare. This tree should never be planted where sunlight 
is wanted winter or summer. 




Fig. 28. Beech. This and other trees grown on a lawn not sacri- 
ficed when street was cut through. Courtesy of 
Newark Shade Tree Commission.^ 



CATALPA. 

All the species of catalpa should be considered ornamental 
rather than practical shade trees. The southern catalpa 
(Catalpa catalpa, Ivarst) is a scrawny, irregular tree, but 
very picturesque in maturity, especially when covered with 
its large white bloom. The foliage and flowers appear quite 
late, and the leaves are blackened by the first frost or often at- 
tacked by fungi. The hardy cataljja (Catalpa speciosa, En- 



Most Available Teees for Planting. 59 

gelm) grows more upright and is sometimes used as a shade 
tree, yet its large tender leaves, susceptible to frost as well 
as to burning by reflected heat, make it undesirable. The 
Japanese sjjecies (Catalpa bungei and C. haempferi) are 
purely ornamentals of small size. 



CHESTNUT. 

This is a Jarge tree of very rapid growth (Castanea den- 
tata, Borkh), and formerly was one of the most valuable na- 
tive species, but since the appearance of the bark disease (see 
page 101), not a single chestnut tree should be planted any- 
where. The paragon, or large fruited chestnut, from Europe 
is advocated for its nuts, but it is apparentl}^ susceptible to 
the same disease. 

ELM. 

No other tree, native or foreign, combines so many de- 
sirable qualities for a street tree as the American, or white, 
elra (Ulmus Americana, L.) It grows too large for narrow 
streets, but for those of moderate width, and for avenues, it 
has no superior. The trunk commonly divides at from ten 
to fifteen feet above the ground and forms a broad, high- 
arching crown with pendent branchL^rs. The tree requires 
reasonably good soil and plenty of moisture, and under fa- 
vorable conditions grows comparatively rapidly. The leaves 
are rather small and the shade produced not too dense. The 
autumn foliage is not notable. White elm is subject to 
several diseases, but throughout j^ew England, and in this 
State, its chief enemy is an insect called the elm leaf beetle. 
(See page 67.) This, however, should not deter anyone 
from j)lanting the tree for the insects can always be con- 
trolled. Slippery elm (JJhnus fulva, Michx.), and other na- 
tive species have no especially desirable qualities as shade 
trees. The English field elm {Ulmus campestris L.) and the 
Scotch elm {Ulmus montana, Bauh.) are sometimes planted 
as ornamentals. 



60 



Shade Trees. 




Fig. 29. Neither new road nor new trees require the sacrifice 
of a fine old elm. 



GINKGO. 



A tree {Ginkgo hiloba, L.) introduced thirty or forty years 
ago from Eastern Asia. It grows rapidly on almost any 
soil, develops a narrow cylindrical or conical crown that 
adapts it well to narrow streets, and is apparently not af- 
fected by insects or disease. The fan-shaped leaves with 
straight veins are unlike those of any native tree and their 
bright coloring in the fall sometimes rivals that of the 
maples. The only objection thus far made to the ginkgo 
as a street tree is that its fruit, an oily nnt, is sometimes 
malodorous. Even where the heat reflected from paved 
streets is considerable the tree thrives. It promises to be 
one of our most valuable species. 



Most Available Trees foe Planting. 61 



GUM. 



Of the various gum trees only sweet gum, or bilsted 
(Liquidamhar stijraciflua, L.) is suitable for street plant- 
ing. This, hoAvever, is one of the very best, since it adapts 
itself to many conditions, develops a symmetrical, narrow 
crown, and is most attractive throughout the year. The 
tree prefers moist, even wet ground, but grows fairly well 
under less favorable conditions. Extreme care must be ex- 
ercised in transplanting as the roots are tender and lose their 
vitality if allowed to dry. The star-shaped leaves color 
gorgeously in the fall, and when they are gone the pendent 
spiky fruit heads adorn the tree throughout the winter. 
Many of the branches are furnished with curious corky 
ridges, or wings, sometimes upwards of an inch in width. 

Sour gum, or black gum (Nyssa sylvatica. Marsh.) , also 
called tupelo, and pepperidge, is a tree of quite different 
character. It grows under most adverse conditions, but is 
apparently not well suited for street planting. As an orna- 
mental, however, it well deserves a place. 

HACKBERRY. 

A tree (Celtis occidentalis, L.) closely related to the elms, 
but of more upright habit and thrifty in poor soils. It is 
especially well suited to narrow and moderately wide streets 
and to the most trying conditions. Almost every mature 
tree exhibits curiously knotted branehlets called "witches 
broom," the result of disease. This, however, does no ma- 
terial harm. (See page 106.) 

HORSE CHESTNUT. 

A tree (Aesculus hippocastanum, L.) native to the Medi- 
terranean countries, and often planted in the cities of 
Europe, yet not especially valuable there or here. Its fine 
form, beautiful leaves, which unfold very early, and great 
panicles of white flowers are its chief recommendations. It 
is also hardy in moderately good soil, and grows with fair 



62 



Shade Trees. 



rapidity. Against these recomniendations must be set its 
susceptibility to insect and fungus attack, the early fall of 
its leaves, the litter produced by its fruit and the liability 
to injury by reflected heat when planted on sunny streets. 
A tree of undoubted value for parkways and lawns, but it 
should be used with discrimination in other situations. One 
or two native horse chestnuts, or buckeyes, especially A. 
glabra. Wild and A., octandra, Marsh., are also sometimes 
planted. 

LOCUST. 

Common, black, or yellow locust (Robinia pseudacacia, 
L.) is so subject to injury by the borer worm (see page 83) 
that it should never be planted in this part of the country, 
either along the streets or on lavms. This is unfortunate 
because the light foliage and narrow form of the crown, 
with the hardiness and adaptability of the tree, make it an 
admirable one for street planting. Honey locust (Gleditsia 
triacanthos, L.), however, is less apt to be injured in this 
way. The tree is very hardy, not particular about the soil 
in which it stands, and a fairly rapid grower. Apart from 
the beauty of the foliage, which is Linusually light and open, 
the flowers are full of honey and the stout thorns with which 
the trunk and branches are clothed make it particularly at- 




Fig. 30. Trees left above grade. If others are planted at x, x, x, the old 
ones can be removed in a few years without injuring the property. 



Most Available Trees for Planting. 63 

tractive. If these thorns are objectionable they can be re- 
moved or a thornless horticultural form may be used. The 
tree is somewhat late in unfolding its leaves, yet that is 
hardly a disadvantage. The long, coarse, pods that litter the 
pavements in the fall, or hang on the branches in winter, are 
more objectionable. 

MAPLE. 

ISio trees have been more widely used for street planting 
than the maples, yet in too many cases the wrong species has 
been employed, or the trees used in situations to which they 
are not suited. White, silver or soft maple (Acer sacchari- 
num, L.) is planted ever^'where, yet it is a poor tree, and 
for the reasons given on page 13 is not recommended. ITor- 
way maple {A. platanoides, L.) is altogether the best tree 
that we have for streets of moderate width. It is symmetri- 
cal in form, adaptable to almost any soil, hardy, and a fairly 
j-apid grower. In autumn its foliage takes on the most bril- 
liant coloring. The tree is little subject to serious diseases. 
Though several insects frequently attack it they usually do 
little harm. The drying of the leaves often noticed in early 
summer is usually due to deficient moisture, or to sunburn. 
It is to be prevented whenever possibl.?, though it rarely does 
harm. (See page 116.) Eed maple {A. ruhrum, L.) is of 
somewhat more slender habit than Norway maple and thrives 
best in moist soil. It also is a good tree for streets of mod- 
erate width, though it sometimes suffers from sunburn. The 
vouuffer branches are reddish and in autumn the coloring of 
rhe foliage is brilliant. Sugar maple {A. saccharum, 
Marsh. ) is a larger tree than ISTorway maple, though in many 
respects so much like it that the two are often hard to dis- 
tinguish. It thrives in cool situations, but invariably suffers 
when planted along paved streets. Except on wide streets 
with parking the ISTorway maple is always to be preferred. 
Ash-leaved maple, or box elder (A. negundo, L.) is a small 
tree whose only merit is that it accommodates itself to ad- 
verse conditions. It is short lived like silver maple, and is 
not recommended for the same reasons. 



64- Shade Trees, 



OAK. 

It is decided] V iinfortunate that the many oaks found in 
this country have not furnished more street trees. As a 
family they are undoubtedly the best shade trees that we 
have, for, with few exceptions, they are beautiful, long lived, 
and little subject to insects or disease. When properly 
planted and taken care of the growth of many of them is not 
slow. The following species are recommended. Red oak 
{Quercus rubra, L.), one of our grandest forest trees, is suit- 
able for broad avenues. It is satisfied with comparatively 
poor soil, develops a straight, sturdy trunk surmounted by 
a broad symmetrical crown, not too dense, and its foliage 
turns a brilliant color in autumn. It is the most rapid grow- 
ing of the oaks. Scarlet oak {Q. coccinea, Muench.) is much 
like red oak, but smaller in size, and does well on even poorer 
soil. Its leaves also are brilliantly colored in the fall, and 
quite persistent. Pin oak {Q. palustris, Muench.) grows 
taller and more slender than most other oaks and has an 
unusually straight stem. It is thoroughly at home on moist 
ground, but does not do well where it is dvj. The leaves 
are less brilliantly colored than those of red and scarlet 
oaks and are apt to persist through the winter. Several fine 
avenues of this tree may be seen in Washington, D. C, and 
on Long Island. The white oaks, including bur oak, swamp 
white oak, chestnut oak and the English oak, are less valu- 
able for street planting than for la^vns. All are compara- 
tively short but sturdy and with broad crowns. They are 
the longest lived of all our deciduous trees, and, contrary to 
the general impression, not at all slow growing when suitably 
located, 

SYCAMORE. 

A tree (Platcmus occidentalis, L.) which normally, and 
under fa^^orable conditions, grows to an enormous size, but is 
capable of being pruned and trained to meet the conditions 
imposed by streets of moderate width. It prefers a rich. 



Most Available Tkees foe Planting. 65 

moist soil and in that grows very rapidly. Its peculiar habit 
of shedding its bark every year especially adapts it to loca- 
tions in which there is much smoke. The leaves unfold late 
and are not brilliantly colored in the fall, but the globular 
fruit which persists through the winter, the free habit of the 
tree and its vigorous growth, recommend it highly. In some 
localities a fungus attacks the leaves just after they unfold, 
but the injury is not apt to be very serious or permanent. 
(See page 97.) Some planters prefer the European syca- 
more, or plane tree (P. orientalis, L.), yet its superiority is 
at least doubtful. It is said that one-third the trees planted 
in Paris are American sycamores. 



TULIP POPLAR. 

Liriodendron tulipifera, L., a magTiificent tree suitable 
only for wide avenues with broad grass spaces, or for lawns. 
It absolutely requires good, well-drained soil ; when that is 
given it grows with unusual rapidity and forms a tall, 
straight trunk Avith a comparatively narrow crown. Under 
other conditions it suffers from sunburn and manv diseases. 



Insects Injurious to Shade Trees. 

By John B. Smith^ Sc.D.^ Siate Entomologist. " 

GENERAL CONSIDERATIONS. 

lu the following pages it is intended to refer to the lead- 
ing species of insects infesting shade trees in the briefest 
possible manner only and to give, in the same way, directions 
for treatment. If further details are desired concerning 
the habits or characters of the insects referred to, they can 
be found in the Bulletins and Reports of the Fniierin- 
ISTew Jersey Agricultural Experiment Stations, obtainable. 
to wdiich reference is also made for further information con- 
cerning insecticides and insecticide machinery. 

The colored plates exhibiting the more important insects 
were prepared by Mr. John A. Grossbeck, then an assistant 
in the author's laboratory. The drawings were made from 
published figures, credited as to source in Bulletin 181 of 
the 'New Jersey Agricultural Experiment Stations. 

The order in which the insects are referred to here, is an 
indication of their relative importance. 

THE ELM-LEAF BEETLE. 
PI. IV., Figs. 5, 5a, 5b. 

The adiilt beetle lives through the winter, hiding in attics 
and other sheltered places. When the first elm leaves are 
full grown in syjring it becomes active, begins eating irregu- 
lar holes through the leaves and, in about a week, laj's eggs. 
These hatch into yellow and black slugs which attacks 
feed on the underside of the leaves, eating only *■*'"•" *"'''• 
the surface layer of cells, and cause them, to turn brown, dry 
and drop. Early in July the larvse crawl to the base of the 

*Died March 12th, 1912. 

(67) 



68 Shadr Tkees. 

tree, cliange to yellow pupse and bj August 1st have changed 
to beetles. These feed for a few days and then go into hid- 
ing, to reappear the spring following. Attack elms only. 



Remedial Measures. 

Spray the infested trees with Paris green, 1 pound in 125 
gallons of water, or, preferably, 1 pound of dry arsenate of 
lead in 25 gallons of water, as soon as the first beetle is seen 
feeding in spring, and soak the leaves thoroughly. The ob- 
ject is to kill the beetles before they can lay eggs, and there- 
fore j)3'omptness and thoroughness are essential. (See page 
88.) 

If there has been delay and some eggs are already laid, it 

will be desirable to spray a second time as soon as larval 

feeding is observed, and this time every effort 

TMs win ^ 1 • 1 1 <■ 11 

prevent ser- must DC made to hit the leaves from the under- 
side, because there is where the larvae feed. 
If, nevertheless, any considerable number of slugs come 
to the ground to pupate, kill them off with boiling hot water 
or bj' sprinkling with kerosene. Cotton batting or sticky 
bands do no e'ood. 



THE WHITE-MARKED TUSSOCK MOTH. 
Plate v., Figs. 2, 2a, 2b, 2c, 2d. 

AVinters on the trees in the egg-stago, in a little white mass 
on the cocoon of the female. Young caterpillars hatch in 
May and feed on almost all ordinary shade trees. Cater- 
pillars when full grown have a bright red head, long pencils 
of black hair fore and aft, and stubby brushes of yellow hair 
on the back. General color yellow with a black 
Various stripe on back. Become full grown toward end 

frees. . 

of June and spin up any^vhere on trees, on 
fences, under window ledges and other shelter on houses. 
In July the males emerge as dusty gray moths v,diich flutter 



Insects Iistjueious to Shade Trees. 69 

about in the early evening and seek the females which are 
wingless and rest on the cocoons out of which they emerged. 
The females lay egg-masses on these cocoons, cover them with 
a snow-white frothy secretion and die. Some of these eggs 
hatch and there is a partial second brood ; abundant in South 
Jersey, scant in ISTorth Jersey. 



Remedial Measures. 

Clean off all egg-masses on trees during winter and band 
the trees in early J\lay with fluffy cotton to prevent cater- 
pillars from getting up from other trees. If the trees are 
infested spray with Paris green or arsenate of Band trees 
lead as prescribed for elm-leaf beetle. Arse- ***' **•*'*• 
nate of lead sticks better, never hurts foliage and, if well ap- 
plied, needs only one application. The earlier it is used after 
infestation is noted the better results V\^ill be. 



THE BAG-WORM, DROP-WORM OR BASKET- WORM. 
Plate v., Figs. 3, 3a, 3b, 3c, 3d. 

Winters in the egg-stage in a gray silken bag or sack, which 
may be found attached to trees and shrubs of almost all kinds, 
coniferous as well as deciduous. The eggs hatch in May and 
the young caterpillars at once make a little bag or sack which 
is enlarged as they grow and in which they live 

Attacks all 

during their caterpillar life. Teed on the foli- kinds of 

"trees* 

age, openly until July, then change to pupse 
within their bags and in August the male moth emerges. 
This is black, very active, with transparent wings and is 
rarely seen. The female does not leave the bag but, after 
impregnation, lays her eggs in a mass of orange cottony ma- 
terial, then wriggles to the opening, drops to the ground and 
dies. 



70 Shade Trees. 



EXPLANATION OF PLATE IV. 

1. 3. The Cottonj- Maple Scale; Pulvinaria innumeraiilis. 
la. Pulvinaria acericola; found only on leaves. 

2. The Oyster-shell Scale, Mytilaspis pomorum, natural size. 
2a. " " " female, enlarged. 

2b. " " " male, enlarged. 

3. Cottony Maple Scale, male, enlarged. 

3a. " " " one of the recent sets, enlarged. 

4. The Scurfy Scale, Chioiiaspis furfurus, natural size. 
4a. " " " female, enlarged. 

4b. " " " male, enlarged. 

5. Elm leaf with Eggs and Larvae of The Elm-leaf Beetle, Galerucella 

Jiiteola, natural size. 

5a. Elm-leaf Beetle larva, enlarged. 
5b. Adult Elm-leaf Beetle. 

6. San Jose Scale. AspicUotus perniciosus, enlarged. See Pig. 82. 




PLATE IV: See descriptions opposite 








^">N^, 




-% 




''••/•n Kycy ..'.-.*. 

» 1'* ,.".'.''.■ ' ♦ * ' ' * • " "!,''r, f 



fc 





PLATE V: See descriptions opposite 



L\SECTS llN^JUKIOUS TO ShADE TeEES. Yl 



EXPLANATION OF PLATE V. 

1. The Fall AYeb-Worm ; Hypliantria eiinca — adult laj'ing eggs. 
la. " " " adult moth expanded. 

lb. " " " pupa. 

Ic. " " " larva. 

Id. " " " varietal larva. 

2. The White-marked Tussock Moth ; 'Notoloplius leucostigma, larva. 
2a. " " " " female pupa. 

2b. " " " " male pupa. 

2c. " " " " female on egg mass. 

2d. " " " " male moth, natural position. 

3. The Bag- Worm ; Thyridopteryx ephemerceformis, male adult. 
3a. " " over-wintering bag which contains the eggs. 
3b. " " larva. 

3c. " " female pupa. 

.3d. " " male pupa. 

4. The Wood Leopard Moth ; Zeiizera pyrixa, male. 
4a. " " " " larva from above. 

4b. " " " " larva from side. 

4c. Work of the larva of the Wood Leopard Moth. 



Shade Tkees. 



Bemedial Measures. 



On shrubs, and especially Arborvitse and other ever- 
greens, pick off the bags during the winter and burn them. 
On trees, where that is not feasible, spray thoroughly with 
arsenate of lead or Paris green as recommended for the elm- 
Piek off -^^^f beetle, just as soon as the young caterpillars 

''^^*' are observed issuing from the bags. Conifers 

will not stand Paris green, but may be safely treated with 
arsenate of lead. There is only one brood of this species and 
winter work is especially recommended on hedge plants which 
are sometimes dense and not easily sprayed. 



THE COTTONY MAPLE SCALE. 
Plate IV., Figs. 1, 3, 3a. 

Attacks Maples only, among shade trees ; but found also 
on Vitis, Ampelopsis and other plants. The impregnated 
female winters as a brown scale on the twigs, resumes feeding 
in May, and late in that month or in early June begins to 
exude a white cottony mass in which a thousand eggs or 
Attacks more are laid. The minute young hatch in late 

trees,"*but* Juue or early July, crawl about a few hours 
other plants. ^^^^^ then sct ou Icaves, twigs and branches and 
suck the juices. When the insects are abundant, the leaves 
turn a sickly yellow, often become covered with honey dew, 
and badly infested branches may die. The insects mature in 
late August and September; the males issue as minute 2- 
winged flies, impregnate the female and die. The latter 
move from leaves to twigs and fix themselves firmly for the 
winter. 



IisrsECTs Tnjueious to Shade Teees. 73 



Remedial Measures. 

This species is ordinarily kept in check by its natural 
enemies ; bnt sometimes it escapes and becomes conspicuously 
abundant. It is always well, where easily accessible twigs 
are observed with forming white cottony masses in June, 
to cut them ofl" and destroy them by fire, and ordinarily 

-, . . -,. ' -, n T • needs no 

this may m ordinary seasons be all that is neces- control. 
sary. If the infestation is very bad, cut off an infested twig 
in late June and lay it in a box on a sheet of white paper. 
When the paper becomes covered with rusty crawling dust- 
like particles the young are hatching, rhen spray the infested 
portions of the tree with whale-oil soap, 1 pound in 4 gallons 
of water, or with kerosene emulsion 1 part to 12 parts of 
water. (See also page 78.) 



THE WOOD LEOPARD MOTH. 
Plate v., Figs. 4, 4a, 4b, 4c. 

This insect winters in the caterpillar stage in the wood of a 
great variety of deciduous shade and fruit trees, favoring 
maple and elm among the former. They live in the trees as 
borers for two full years, and in the spring of the third 
change to a pupa and then to an adult which is a large white 
moth with black spots, the males being strongly Attacks 
attracted to the electric light. The full-grown ^f'*?Je^s***bHt 
borer is two inches or more in length and often locaiiy. 
girdles branches of considerable size, or even the trunks of 
small trees. It is common only in the cities and towns in 
the east central part of the State from Paterson to Long 
Branch and west to ISTew Brunswick, doing its greatest mis- 
chief in the largest cities where the English sparrows exclude 
the native birds. 



74 Shade Teees. 



Bemedial Measures. 

On small trees the borers can be often found and cut out 
or destroyed with a soft Avire run into their burrow, which 
opens outwardly, or bisulphide of carbon may be injected. 
(See page 83.) On larger trees gather and burn all the 
twigs and branches that fall to the ground or are blown 
down in high winds. Where dying branches are noticed, 
Kill one by ^^^ them o£t" bclow the point of apparent injury 
*"**• and burn the cuttings. Inject bisulphide of 

carbon into all holes from which strings of sawdust are ob- 
served exuding, and plug up the opening with putty. When 
the moths are observed around the electric or other lights 
kill every one that comes within reach. Discourage spar- 
rows and favor all other birds that come into town. 



OYSTER-SHELL BARK-LOUSE. 
Plate IV., Figs. 2, 2a, 2b. 

This is the most common of the armored scales attacking 
shade trees, and derives its name from the reseiublance to 
one of the very elongate type of oysters. It winters in the 
egg stage under the scale, and in May or June the eggs hatch 
into minute yellow crawling atoms thar,, in 24 hours, set and 
begin to form small scales. These suck the juices of the 
twigs and increase in size until midsummer or 

Attacks 

many trees a little later. Thcu the males mature as small, 
two-winged flies, and the females, after im- 
pregnation, lay their yellowish white eggs which fill the space 
beneath the scale as the mother gradually shrivels up. South 
of the red shale line the tendency is to a second brood of these 
scales and in the sandy pine region the second brood is well 
defined. ]^orth of the red shale there is only one brood. 
Maples in South Jersey are often very seriously injured. 



Insects Injurious to Shade Teees. 75 



Remedial Measures. 

There is only one period at which this insect can be satis- 
factorily reached ; that is when the eggs have just hatched, 
and while the larvse are moving about or have just set. The 
exact date cannot be given because it varies with the season 
and with the section of the State; but it will be during late 
May or early June. As soon as the larv^ are ^^^^^ ^^ 
observed, spray with whale-oil soa]) at the rate *"*^*'* "™^- 
of 1 pound in 5 gallons of water, or kerosene emulsion 1 part 
to 12 parts of water. Eepeat if possible a week afterward, 
to reach delayed larvse. This will usually prove effective, 
and will aid the natural enemies in getting control of the 
insects. AV inter sprays are not useful against this species 
because the eggs are not affected beneath their scaly covering. 



THE FALL WEB-WORM. 
Plate v., Figs. 1, la, lb, Ic, Id. 

This species winters in the pupal stage, and early in May 
the adult moth appears as a medium sized snow-white miller, 
sometimes more or less black dotted. It lays its eggs in a 
mass on the underside of a leaf, and the little caterpillars 
that hatch from them remain together, spinning Attacks 
a web in which they live and from which they eVduoH^f" 
emerge at night to feed. As they grow, the **'•'*'*• 
nest increases in size and may measure two or even three feet 
across, in large colonies. In July these caterpillars are ma- 
ture, pupate and soon after produce a second crop of moths 
which in turn lay eggs from which caterpillars hatch in Au- 
gust, the nests becoming conspicuous late in that month or 
early in September. Because most people notice them only 
at that season they have received the name fall web-worm 



76 Shade Teees. 

to distinguish them from the tent caterpillars in apple 
orchards which are most conspicuous in spring. Linden or 
basswood among the shade trees suffers most from this web- 
worm which, however, may be found on a great variety of 
deciduous trees. 

Remedial Measures. 

When a forming nest of these caterpillars is observed burn 
it with a long handled torch, cut it off and tramp it under 
foot or otherwise destroy it. When the nests are not ac- 
Destroy ccssiblc or havc become so large that cutting 

******* would mutilate the tree, spray the foliage 

around the nests with Paris green or arsenate of lead as 
recommended for the elm-leaf beetle. It is not necessary to 
spray the entire tree, for the caterpillars do not move further 
from their nest than necessary to find food; hence spraying 
the vicinitv of the nest is all that is needed. 



THE MAPLE PSEUDOCOCCUS. 

Late in the summer the trunks, and sometimes the 
branches, of sugar maples become covered with a white cot- 
tony or waxy substance, beneath which will be found yel- 
lowish, crawling, grub-like creatures. These sometimes in- 
crease so greatly in number that they form ver- 

Attacks . , . 

s«sar itable layers, coating the trunks completely and 

maples only. t i x ./ 

extending to the leaves. When the latter are 
attacked they are apt to turn yellow and drop, so that in 
severe cases a tree becomes partly defoliated earlier in the 
season than is normal. The insect winters in the partly 
grown condition, hiding in the crevices of the bark, and not 
until after mid-summer does it usually become abundant 
enough to attract attention. 



Insects Injurious to Shade Trees. 



77 




Fio-. 31. The Maple Pseudococcus : o, the cottony masses covering the 
" adult females on leaf ; b, young of both sexes on bark 

From Howard, U. S. Dept. Agl. 



Remedial Measures. 

When the infested leaves drop to the ground they should 
be regularly raked u]-) and burnt. In the cities and towns 
where water pressure is available, a solid jet from a hose on 
the infested trunk will wash out and destroy the ^^ash ^vitu 
vast majority of the specimens, leaving not •'»^''' 
enough to do any harm. In winter the tree trunks may be 
sprayed with one of the miscible oils like ''Scalecide," di- 
luted Avith ten parts of water and applied with sufficient force 



7S Shade Trees. 

to penetrate into every crevice and irregularity of the bark. 
This will kill the hibernating forms and prevent any start 
next season. 

Incidentally, the forcible solid jet just recommended, may 
bo applied with a pump and small nozzle, and this has also 
been used to dislodge the cottony maple scales (see page 73) 
from twigs and branches early in the season before the eggs 
have hatched. 

THE SCURFY SCALE. 
Plate IV., Figs. 4, 4a, 4b. 

This scale infests the poplar most frequently, among the 
shade trees, but is also found on maple and occasionally on 
others. It is very pale gray, almost as broad as long, with 
Attacks a yellowish point or head. Beneath this scale 

chiefly. the purplc eggs are found during the winter, 

and in June they hatch into purplish crawling larvae which 
ha^'e the same general habits of other scale insects, and like 
them suck the plant juices. There is only a single brood 
which matures in September, and is rarely abundant enough 
to do any real injury. 

Remedial Measures. 

This scale is thinner than most others of the armored 
forms, and may be reached by the lime-sulphur or other caus- 
tic sprays in winter. The caustic corrodes the scaly cover- 
if serious ^^o? ^^^ ^hc eggs wash out and are scattered 

use caustic. ^^^ destroyed on the ground. Even caustic 
lye or soda at the rate of 1 pound in 1 gallon of water will 
accomplish this. If no winter application is made it will be 
necessary to wait until the eggs hatch in June, and then 
apply whale-oil soap or kerosene emulsion as recommended 
for the oyster-shell scale. 



IjN'sects InjupvIOus to Shade Tkees. 



79 



THE SAN JOSE SCALE. 
Plate IV., Fig. 6 ; Fig. 32. 



This is a small, round, blackish scale that passes the winter 
in the partly gro^wn condition, comes to maturity in early 
June, bears living young and reproduces throughout the sea- 
son so that a slight infestation in spring may mean seriou.s 
danger before the year is over. JSiot many of the ordinary 
shade trees are subject to dangerous infestation 
M^hen well grown; but young elms, especially 
of the European varieties, are sometimes much 
injured and occasionally killed. 



Attacks 
fruit trees 
more than 
shade trees. 




Fig. 32. The San Jose Scale : a, on a twig, natnral size ; 6, as seen under a 
hand lens, much enlarged. Div. Ent., U. S. Dept Agl. 



80 Shade Trees. 



Remedial Measures. 

As this insect bears its young alive, the period of reproduc- 
tion is spread over a considerable period, and no one applica- 
tion can reach all, or even a large percentage, of the larvae in 
the naked condition. In consequence, winter 
applications that are either very caustic or very 
penetrating are resorted to. The caustics are the lime and 
sulphur washes or whale-oil soap, the latter at the rate of two 
pounds in one gallon of water. The penetrating materials 
are petroleum oils, either undiluted or made miscible, or 
"soluble," in water. The latter are used at the rate of 1 part 
in 15 parts of water and the application must be very thor- 
ough to be satisfactorily eifective. This is perhaps the most 
dangerous of all the scales and the hardest to control in the 
orchards. Fortunately none of our usual city trees seem to 
its liking, nor does it occur in our forests, although it is able 
to maintain itself on a number of our forest trees. 



THE TULIP SOFT SCALE. 

This is a very large, livid gray scale, nearly 14 of ^'^ inoh. 
in length, almost as wide and very convex. It occurs only 
on the tulip tree but sometimes infests that in great num- 
bers and does more or less mischief, especially on young 
Attacks trees. It winters in the young stages on the 

tulip tree . i i n i i • 

only. tvv^igs, oiten underneath old scales, begins 

growth in May and reaches maturity in August when the 
female is very offensive in odor and filled with a rank pur- 
]3lish material. In early September the small black young 
are born in great numbers and may set on the twigs so 
densely as to completely obscure the natural color of the bark. 



I]MSECTs I:srjuEious TO Shade Trees. 



81 




Fig. 33. A soft scale as it appears on badly-infested twigs. 



Remedial Measures. 



About the only really satisfactory application is undiluted 
crude petroleum as a winter spray. The miscible oils di- 
luted no more than ten times, may answer the purpose ; but 
have not been sufficiently tested. Whale-oil ^. 

, . " jNot often 

soap at the rate ol 1 pound in 4 gallons of water iiarmfui. 
applied just after they are hatched will kill the young, and 
this sort of application is feasible on small or moderate sized 
trees. On very large trees only the winter applications are 
at all practical. Fortunately this insect has some very ef- 
fective natural checks which usually control it, so that except 
ou young trees we need not often ap]ily treatments. 



OTHER SCALES. 



There are a variety of other scales, mostly allies of those 
already mentioned, that at times infest shade trees, but rarely 
in sufficient numbers to require active treatment. As a rule 
winter treatments should be made if the species permits, for 
there is not at that season any interference of foliao-e and 
much stronger mixtures can be used on dormant trees. 

G 



S3 



SirAni-; Tl'kes. 



wonkeneil 



lUHUOUS. 

A ViU'ioty ol" boivrs iufcsl sliadc trin^s ami, as a nilo, they 
attaelv, bv pr(>t\>r(^iu'(\ sueli as are weak ami siekly. But 
lliat is bv no lueaus a iinivevsal rule. ]\Iaple 
trees ari> iiol iufn'(|mMitl_v iirfesteii by a suiall 
eatcn'piUar borer that works into the heart-wood 
though il does little danuvgv unless water finds entrauee 
thvoug'h their holes and eanst-s deeay. (^8ee page 1 iW) The 
holes through whieh they emerge are not o\er 's i^^^^'h in di- 
anu^ter and nt>arly round. The moth is a pretty, elear- 
winged species, yellow, with bright red nnirkiugs. 




b'ig. ;'.{. The Maplo 'Proo Sosiid : a, the larva ; /*. cocoons in cavities made 

l>v larviv ; c, llio adult moth; (/, pupa-shell projecting from trunk. 

After Kiley. 

As against this species frequent whitewashing the infested 
trunks and sealing up the holes with putty, is about the only 
thing that can be done, unless there is a decayed area acting 
as the eentri^ ot" iirt'estation. In that case the cavity should 
be thor^nighly c'leaued and treated as described on page 45. 



Insects Injurious to Shade Trees. 83 

In fact, tlic sort of troatiiieiit onlliuca in the above para- 
graph may be aclopted against borers in general. Sometimes, 
when sawdust is noticed coming out of an opening, the injec- 
tion of disnlphidc of carbon is indicated, plugging np with 
pntty after the injection to prevent the cscapeof the fnmes. 
Carbon disnlphidc mav bc^ injected with a syringe, or even 
the ordinary pipette with rubber bulb such as is used in fill- 
ing fountain pens. I have a long glass tube drawn to a 
point, with a large rubber bulb at the squared end, which 
answers perfectly. It needs only a half teaspoon to a tea- 
spoonful in any case. 

Flat headed borers and bark beetles prefer trees that are 
weak or sickly and, in a general way, it pays to keep trees in 
vigorous health because of their smaller liability to borer in- 
festation. When a tree is once badly infested, especially 
with bark beetles, the sooner it is cut out the better. It is 
simply a source of infection to its surroundings. 

Hickory, and still more often Locust, is very subject to 
the attacks of round-headed borers, and these attack perfectly 
sound trees. 

Locust Borer. 

Th(^ work of this insect is very common on the black or 
yellow locust in Kew Jersey, making it an almost impossible 
tree. As soon as a tree attains a moderate size 
it is apt to be riddled with the large holes made b^aok^'ocust 
by the larvie and leads but a sickly life, if it ""'''• 
does not die within a few years. 

The beetles themselves are rather attractive creatures, 
about three-fourths of an inch long, of a dull black color, 
brightly marked with golden yellow, and may be found fre- 
qu(^nting the flowers of the goldenrod. In September these 
beetles gather on the locust trees and mate, after which the 
feuiale deposits her snow white eggs in cracks and crevices. 
These soon hatch and the grubs bore into the bark feeding on 
the soft inner substance. During the winter they are torpid. 
In spring they resume feeding, boring through the sapwood 



84 Shade Trees. 

and making irregular passages more or less deeply into the 
trunk. Honey locust is little, or not at all, subject to injury 
by tbis insect. 

Bemedial Measures. 

Ordinarily it is impossible to do much to control this in- 
sect. Some persons have suggested a repellant wash to pre- 
vent egg deposition. It is certainly advisable 



ctive +^ ,,„f , 
remedy 



No effective ^q ^^^^ ,^y^^^ bum badly infested trees during, the 



winter. The beetle seems to like the sun and 
has a preference for trees somewhat exposed, therefore, thick 
shady groves would be least likely to be attacked. 



HiCKOEY Bark Beetle. 

This beetle occurs throughout the State, boring under the 
bark of feeble or dying hickories, often killing shade trees 
that would otherwise have recovered under stimulating treat- 
ment. The beetles, which are small, bro^vn or 
only to black, about one-fifth of an inch long, appear 

^Teak trees. , o/ i x 

from the latter i^art of June to the latter part 
of J uly. Attacking the bark of the trunk and large branches, 
each female makes a vertical gallery an inch or more in 
length. JSfotches are cut in the sides of this burrow, for the 
purpose of holding the eggs. After hatching, the grubs 
construct channels diverging from the main gallery. (See 
Fig. 35.) The winter is passed by the nearly full grown 
grubs, which pupate the following spring. 



IxsECTs liSTjuRiors TO Shade Trees. 



85 




Fig. 35. Work of the hickory bark beetle. 



lie me dial Measures. 

"Where a slight infestation is noticed on a tolerably healthy 
tree, the tree should be stimulated by means of appropriate 
fertilizers (see page 25), and the trunk kept 
covered by whitewash to which Paris ffreen has stimulate 

/ o good trees. 

been added, fetrong whale-oil soap suds will 
answer the same purpose. If a tree is seriously infested, it 
should be cut down at once and burned, as it is certain to 
die in a short time anyhow and is only a menace to surround- 
ing trees. 

PLANT LICE. 



^[ost of our shade trees suffer from plant lice to a greater 
or less extent, and none more than the Norway maples. 
These insects multiply very rapidly, suck the juices of the 



86 Shade Tkees. 

leaves and succulent shoots, and so exhaust rhtir vitality. 
,, , , AVhen they become abundant the honer dew ex- 

Maple louse. tit • " 

creted by them sometimes covers the leaves with 
a sticky secretion that may be abundant enough to drop to 
the street below. This secretion tends to clog the foliage so 
that it may drop while yet perfectly green, and a black soot 
fiuigus is also likely to develop. Fortunately this sort of 
attack does not continue after the first spell of hot dry 
weather, and during a normal season is not apt to be bad 
at all. 

Remedial Measures. 

As against plant lice of all kinds on shade trees, nothing is 
much better than whale-oil soap suds and this applies not 
AMiaie-oii '^^b" ^*-^ those speclcs that attack the leaves but 
*'*^^' to some that gather along the undersides of 

brandies of conifers. In general, 1 pound in -l gallons of 
water is an effective streno-th, and safe on most kinds of 



foliage. 



INSECTS INJURING CONIFERS. 



Pines and other conifers are not often used as street trees, 
but are not infrequently found in parks and grounds around 
residences. They sutfer from a variety of insects and are 
not easily treated, because they are extremely sensitive to 
most insecticides. Against feeders upon the leaves, arsenate 
of lead is the only arsenical poison that can be 
safely used. "When plant lice attack them, 
whale-oil soap suds, one pound in six gallons of water, lib- 
erally applied, will be safe and reasonably etfective. Against 
tliose woolly species that are frequently found massed against 
the underside of the branches, a forcible jet of water is often 
very satisfactory or the whale-oil soap may be used, 1 pound 
in -i gallons of water, locally applied. If the trees are suf- 
ficiently valuable, simply scrub the branches with a stiff 
brush and weak soap suds. 



Insects Injurious to Shade Trees. 87 

Scales sometimos infest the needles ; but on large trees arc 
never harmful in inv experience. On small 

1 c 111- • 1 • Scales 

trees watch for Ihe hatcliino' of the eo-gs lu mroiy 
June and use tlu^ Avhalc-oil soa]^ 1 ]H)und m (.i 
gallons, liberally. 

AYliite pines an^ sometimes deformed by the attacks of the 
white-pine weevil which hiys its eggs in the leaders, the larvas 
boring into and killing them. It is the young trees that are 
usually alfected and in most instances the form winte-pinc 
of the tree is permanently spoilt. Fortunately weevil. 
the insect is not at all common in Ncav Jerscv, and vouna; 
trees if kept under observation may be protected by collect- 
ing the adults or, what is more practical, keeping the leaders 
sprayed during J\Iay and June with whale-oil soap suds one 
pound in six gallons of water, adding half a pound of arse- 
nate of lead to this mixture. 

If the leaders are at any time observed to be lacking in 
vigor or to be unnaturally yellow in color, they should be 
carefully examined, and if any signs of feeding are noticed 
every puncture should be followed with a soft wire to reach 
the feeding larvcW If this is done in time the shoot will 
recover. If the feeding is alreadv well advanced so that re- 
covery seems doubtful cut and destroy by fire. 



GENERAL CONSIDERATIONS. 

Shade trees in general should be kept free from dead or 
dying wood, and all cut wood should be destroyed by fire. It 
is always in order to clean the bark during the winter by 
means of soda or lye washes which get rid of the growth in 
or under which many insects hibernate. A 

' . Keep 

strong soap solution, even of ordinarv laundry trees 

•11 c 1 1 1 ,' ' 1 1 • liealtliy. 

soap, will often do a great deal of good, and it 

can be used to advantage on the waxy plant lice or mealy 

scale bugs during the winter. 

AVhen there is an application of an arsenical spray to be 
made, the sooner it is done the better the effect; vouna; or 



88 Sh^\be Teees. 

partly grown specimens succumbing more rapidly and easily 
than more nearly mature forms. A single defoliation rarely 
harms a deciduous tree very much; but successive defolia- 
tions weaken and eventually kill. And always a healthy, 
well fed tree is less attacked by insects than a sickly starved 
example which gives up in despair at the least provocation 
and invites attack bv its verv inabilitv to resist. 



SPRAYING. 

Amoug the first things that must be realized in planning 
work to avoid insect injury to city trees, is that by no means 
all kinds of trees are equally subject to such injury, nor is 
Municipal there any one treatment that is equally effective 

^^**^^- ngaiust all insects. There may be one city with 

1,000 trees on which insect injury may be kej^t down by a 
single man during the season ; another with half that num- 
ber may require a power sprayer and a gang to run it for a 
month. 

At the begiimiug, find out what trees there are and their 
condition. Then, with the assistance of the entomologist, 
you are in position to determine what outfit is needed to carry 
on the work. It is quite possible to get a cheap sprayer, 
which is, at first, adequate when run to the limit ; but no 
piece of inachinerj' does well for any consider- 
machine?"*' ^^^^ period whcu ruu to the limit, and a cheap 
outfit is usually a small one. You can get a 
barrel with a pump that will force a spray to the top of even 
a large elm, and I have personally worked with such an out- 
fit ; but it was hard on the man at the pump, the tendency 
was to lose pressure and too much time was lost in the fre- 
quent tank fillings required. 

Por municipalities with trees running into the thousands, 
power sprayers are essential, but no municipality that needs 
a sprayer at all, should get anything less than a 200-gallon 
tank uY>on which a pump capable of furnishing 100 pounds 
of pressure to two lines of hose should be mounted. The 



Insects Injurious to Shade Trees. 89 

pump need not be of large capacity, for it is not expected 
to throw large quantities of water in a short time; but it 
should have a large air chamber and should be capable of 
supplying a maximum amount of pressure with a minimum 
amount of worl<. The stroke need not be long, but the lever 
should be long and strong, and the pump should be hori- 
zontal, not vertical. An up and down stroke is tiresome and 
cannot be long maintained without losing in strength; a 
liorizontal stroke may be aided by the weight of the body, 
and both or either hand and arm may be used. All these 
matters are important, because upon the amount and uni- 
formitv of the pressure the thoroughness of the _, 

^ 'iL Tlie piunp. 

work depends in large measure. The working 
parts of the pump should be of brass, the valves and packing 
should be of metal and the valve seats should be readily ac- 
cessible. Such a piece of machinery will stand every rea- 
sonable strain that is likely to be put upon it, and will come 
out at the end of the season almost as good as it was at the 
beginning. It will never be worked to its limit in tree spray- 
ing, and with reasonable care will last many years without 
much expense. Such a pump is never cheap at first cost, 
but is a chea]> pump in the long run. Of course no piece 
of apparatus is entirely fool proof, and that fact should be 
kept in mind when hiring men to work it. 

There should be two lines of % hose, best (Quality, each 
100 feet in length, and there should be 6 or 8 foot gas pipe 
spray rods, at the ends of which the nozzles should be fixed. 
There should be a shut-off at the base of each spray-rod and 
one rod should have a solid jet nozzle for reaching the tops 
of trees, while the other should have an adjustable or bor- 
deaux nozzle for making a spray to reach the lower branches. 

As to the poison to be used, there is nothing better than 
arsenate of lead for all leaf-feeding insects, and for choice I 
prefer the dry, powdered form because of its greater con- 
venience in handling and because of its keeping Arsenate 
qualities. If the paste form is used, it should *»* '*'"'^- 
be purchased on guarantee of percentage of arsenic, for it 
runs all the way from 12 per cent, to 20 per cent., and may 



90 Shade Tuees. 

be a pure material in each instance. Anything that runs 15 
per cent, or over is good, and nearly all the leading brands 
sold in the State reach that percentage. The dry material 
runs 30 per cent., and is therefore about twice as strong as 
the average paste. ISTone of the leading brands have more 
than a trace of soluble arsenic, and practically it is impos- 
sible to injure the foliage of any shade tree with any mixture 
likely to be put on by even an ignorant laborer. 

All the commercial tank sprayers have an agitator which 
keeps the spraying mixture stirred while pumping, and some- 
thing of that sort is needed in any case, so as to make sure 
that the material is uniform throughout the spraying period. 

In all cases the poison should be first mixed up with water 
in a pail or tub so as to get it into a smooth thin paste. This 
should be gradually run into the tank while filling, and the 
agitator should be kept constantly going, so as to get a thor- 
stir tbe ouglilv cvcu poisouous iiiixture to start with. 

mixture. Thcu, wliilc a slow Settling does begin almost 

immediately, it is very slow and the mixture can be kept 
in proper shape with very little stirring. It is always better 
to use u]) a tank full of mixture completely, as soon as pos- 
sible after it is made, and it should never be allowed to stand 
over night. It never stirs up quite as completely next day, 
and if part of a tank remains unused at the end of a day's 
work, better take out the plug and let it run to waste than 
try to save it for a future day. 

With a proper outfit and a good crew, the next point is to 
get the material on in such a way as to be most effective. An 
ideally eft'ective application would be one in 
thoroughly! w^hich evorv leaf received an even and complete 
coating of the spray, so that not a particle of 
the foliage could be eaten by any insect without its receiving 
at the same time a dose of poison. As we cannot hope for 
ideally eft'ective work, we must try and get as close to it as 
possible, remembering always that no one insect eats very 
much, and that every female specimen that gets a safe meal 
may lay a batch or two of eggs before getting another, and 
perhaps fatal, bite. 



Insects Injurious to Shade Teees. 91 

The lesson of thoroughness cannot be too strongly incnl- 
cated, and it is better to be wasteful of time and material to 
secure this, than to do much in an unsatisfactory way. Every 
missed branch will stand out later, and to avoid this the crew 
should be taught to work in some systematic manner, so as 
to reach all parts of a tree. 

Concerning the cost of machinery and operation, no one set 
of figures will cover all conditions. A barrel pump outfit 
complete, with a short line of hose, rod and nozzle can be 
had for as low as fifteen or twenty dollars, ^^^^ 
while a power sprayer consisting of an engine, 
pump, 200-g'allon tank and truck may cost from three hun- 
dred dollars up. 

As for the cost of operating, this depends on the size of 
your apparatus, nu.mber of men necessary to operate it, num- 
ber of trees and their accessibility, availability of water and 
in fact numerous other conditions, which will not become 
apparent until the work is under way. Where conditions 
are favorable large trees are often well sprayed for as little 
as one dollar each. Whatever the cost, if one succeeds in 
checking insect ravages, he will be amply repaid by the in- 
creased vigor and beauty of the trees. 



Diseases of Shade and Forest 
Trees. 

By Mel. T. Cook^ State Plant Pathologist. 

The increasing appreciation of the great commercial value 
of our native forests, and of the importance of trees for 
shade and ornamental purposes, has stimulated the study of 
methods for the proper care of trees. This conservation 
movement has been emphasized by the ravages of the chest- 
nut blight, or bark disease, and our growing knowledge of 
other threatening diseases. The fact that it is possible to 
prevent the loss of many fine trees, which it has required 
years to grow, makes it very desirable that we should give 
careful attention to this subject. 

Trees, in fact all other plants, are subject to diseases which 
are due to more or less well kno^vn causes and are as well 
defined as the diseases which attack animals. f„„^^„ ^t 

tonuses OI 

Like the diseases of animals, the diseases of disease. 
plants may cause loss of color, loss of parts, deformities and, 
in some cases, death. The diseases of both animals and 
plants are caused by fungi, bacteria, insects, worms, unfavor- 
able surroundings, etc. Among animals the most common 
causes of disease are bacteria, while among plants the fungi 
are responsible for by far the greater number. 

A fungus is a plant which does not possess the green color- 
ing matter, chlorophyll, and therefore cannot draw its nour- 
ishment from the air, soil and water, but must live upon 
other plants and animals, living or dead. Those which live 
upon and draw their nourishment from living organisms 
are known as parasites and are the causes of 
nianv diseases ; those that live upon dead mat- and 

'-, 1 , mi r- saproyhytes. 

ter are known as saprophytes, ihe fungus 
may be so small as to require the use of the miscroscope in 
order to see it, or it may be a minute thread-like structure 

(93) 



94: Shade Tkees. 

which grows over the surface of, or penetrates, its host, 
eventually coming to the surface to produce its fruiting 
bodies or sporophores. These sporophores may vary in size 
from the microscopic in some species to the very large 
structures of other species which are usually known as mush- 
rooms or toadstools. These familiar fruiting bodies on trees 
may be from parasitic fungi which cause diseases, or they 
may be from saprophytic fungi which follow diseases and 
live on the dead and decaying material. In order to defi- 
nitely determine this point it is necessary for the observer 
to be familiar with the organisms. 

Some of these fungus diseases are very destructive to 
forest, shade and ornamental trees, and every eifort should 
^, ^ „ be made to eradicate or control them, but most 

Not all . _ ' 

fungi of them are of minor importance. The ma- 

dang^erous. . . „ , ^ 

jority 01 the large lungus growths are sapro- 
phytic, and although not the cause of diseases they destroy 
great quantities of timber which would otherwise be useful. 
Tn this paper only the more common and conspicuous dis- 
eases will be discussed, but some others which at the present 
time are of minor importance in the State will be mentioned. 
Any part of the plant, roots, stems, leaves, flowers and 
fruits, are subject to the attack of diseases, but the disease 
ciassifica- is uot always manifest at the point of attack, 
diseases. i. c, a discasc of the roots may frequently be 

detected by a dying of the leaves and branches. For con- 
venience the diseases of trees may be arbitrarily grouped as 
follows : 



1. Diseases of the foliage. 



'2. Diseases of the stems. 

3. Diseases of the roots. 

4. Diseases due to environment. 

5. Other diseases. 



Diseases of Shade and Forest Teees. 



95 



1. DISEASES OF THE FOLIAGE. 

The foliage contains the greater amount of the green color- 
ing matter, or chlorophyll, by which a plant is enabled to 
ntilize the nxw food materials which it receives from the air 
and soil. Therefore any great reduction of the foliage sur- 
face during the growing season results in a proportional 
reduction in the working power of the plant and also mars 
its beauty for ornamental purposes. 




Fig. 36. Chestnut Leaf Spot. (From Report of N. J. Experiment 
Station, 1896, Fig. 59.) 



Leaf Spots. 



These diseases are caused by a number of parasitic organ- 
isms, principally fungi and bacteria, which cause discolored 
areas on the foliage, frequently followed by a breaking out 
of the dead tissues, thus leaving unsightly holes. The char- 
acter and severity of these various leaf spots vary with the 
organisms to which they are due and also with climatic con- 
ditions. Among the most important of these leaf-spot fimgi 



on shade trees are the following 



96 Shade Trees. 

Walnut. Marsonia juglandis Lib. causes a browii spot 
on the black walnut and butternut, gradually increasing in 
size and frequently covering the entire leaflet. 

Chestnut. Marsonia ocliroleuca B. and C. causes nu- 
merous circular, ashy white spots on the chestnut. (Fig. 
36.) The dead tissue of these spots breaks leaving holes 
and the entire leaf finally turns brown and falls prematurely. 

Elm. Dothidea idmi Duv. attacks elms causing con- 
spicuous black spots. Frequently the foliage is badly in- 
fected and the beauty of the tree seriously marred. 

Maples. Rhytisma acenum Pers. attacks many of the 
maples, but is most severe on the silver maple, causing shiny, 
black, hard, slightly elevated patches commonly knovm. as 
tar spots. (See below.) 

Hoese Chestnut. Phyllosticta pavice Desm. is the cause 
of an important leaf spot or blotch. The spots are irregular 
in shape, increase rapidly in size until the greater part of 
the leaf is brown and has the appearance of being sun-burned. 
The leaves fall early and the vitality of the tree is reduced. 
This fungus is frequently accompanied by others which aid 
in its injurious work. 

Catalpa. p. catalpce Ell. and Mart, and Cercospora 
catalpce Wint. are the causes of unsightly leaf spots on the 
catalpa. They are frequently accompanied by Macrosporium 
catalpce E. and M. and Microsphcera elevata Burr. 

Maple. P. acericola C. and E. is the cause of a leaf spot 
of the maple, which is frequently so severe as to cause a pre- 
mature dropping of the foliage. (See above.) 



Treatment. 

The burning of the fallen leaves, thus destroying enormous 
numbers of spores which could otherwise be distributed by 
wind and water, will greatly reduce these diseases. Where 
practical to do so, spraying with Bordeaux mixture will hold 
them in check. 



Diseases of Shade and Forest Trees. 97 



Anthracnoses. 



These diseases are very common and attack many different 
species of plants. They are due to fungi and many of them 
are also found on stems and fruits. On the foliage they 
may cause spots or holes, or a wirhering very 
similar to that caused by frost. syo«n.„re. 

The most important of the anthracnoses on shade and 
ornamental trees is that on the Sycamore, caused by the 
fungus Gnoinoriia veneta^' (Sacc. and Speg.) Kleb. In the 
earlier stages of the disease it follows the veins of the leaves, 
from which it eventually spreads. It also attacks the young 
shoots. In severe cases the leaves are entirely browned and 
withered and have very much the appearance of those in- 
jured by frost, for which the disease is frequently mistaken. 
It often kills the young shoots and sometimes kills the seed- 
lings and young trees. This fungus is also said to cause leaf 
spots on several species of oak. 



Treatment. 

Dead branches should be pruned out and the rough, loose 
bark which may retain the disease should be removed and 
burned. The trees should also be sprayed with copper sul- 
phate or lime-sulphur during the resting perio.l, then with 
Bordeaux mixture soon after opening of the buds, again in 
ten days and again ten days later. 



Powdery Mildews. 

The powdery mildews are due to fungi and are well kno^vn 
on many plants. These fungi, unlike the preceding, do not 

*One stage of this fungus has been described under the name Gloeosporkun 
nervisequmii Fold, by which it was long known and by which is was referred 
to in the Fourth Annual ReiJort of the Forest Park Reservation Commission 
of New Jersey 1908. 



98 Shade Teees. 

penetrate the foliage, except so far as may be necessary for 
the formation of holdfasts, but spread over the 
surface of the foliage forming a delicate white 
web which has much the appearance of dust. 

One of the most important of these mildews is Micrd- 
sphcera aliti (Wallr.) Wint. which attacks lilacs and also 
occurs on the oaks, birches, dog^woods and some other plants. 
Another very common mildew is Uncinida salicis (D. C) 
Wint. which occurs on the poplars and willows. As a rule, 
they do not appear until late in the season and cause very 
little injury except to young trees and nursery stock. 



Treatment. 

SjDraying with iiotassium sulphide (1 lb. to 50 gal. of 
water) is an efficient remedy. 



Leaf Curl. 

The leaf curls are more or less common on many trees, the 
most conspicuous being the one on the peach. The most im- 
portant one on forest and shade trees is due to Taphrina 
Attacks ccerulescens (Mont, and Desm.) Tul. which 

**^^^' attacks the oaks causing the leaves to appear as 

though blistered. It is not often injurious but sometimes 
causes death of trees which have been affected for a number 
of years. 

Treatment. 

The burning of fallen leaves and spraying the trees with 
copper sulphate or lime-sulphur when dormant will practi- 
cally eliminate the pest. 



Diseases or Shade ain'd Foeest Teees. 99 



Rusts. 



The rusts are among the most liighly developed of the 
parasitic fungi and attack foliage and fruit. Some of them 
are very destructive while others are compara- 
tively insignificant. Many of them have very '•"p»''*«"*^*'- 
complicated life histories and require two host plants to com- 
plete their life cycle and in many cases to perpetuate them- 
selves. 

One of the most conspicuous of the rusts is the Gymno- 
sporangium macropus * Lk., which attacks the red cedar and 
the apple. On the red cedar they cause the formation of the 
large reddish brown bodies known as "cedar ^^^^^ 
apples." During the period of early spring Bwies. 
rains the mature cedar apples produce long yellowish or 
oi'ange colored horns within which are produced great masses 
of fungus spores. These spores will not attack the cedar 
but are carried to neighboring apple trees where they attack 
the leaves, and sometimes the young twigs and fruit, causing 
yellowish or reddish orange spots. On the under side of 
each spot are produced a number of small cup-like cavities 
within which are borne the spores. These spores are in turn 
carried to the cedars where they attack the young shoots and 
eventually cause the formation of the next year's crop of 
"cedar apples." 

Treatment. 

This fungus may be held in check by removing the cedar 
apples early in the spring before the maturing of the orange 
colored horns, and by the proper spraying of the apple 
orchards. 

Among other interesting diseases of this kind 
are the rust, or leaf cast, of the Jersey or scrub affected "by* 
pine, the rust of the Scotch and pitch pines 
which has an alternating stage on the sweet fern, the leaf 
rust of the hemlock, rusts of the willows, poplars and ashes. 

*There are several species of Gymnosporanoium attacking cedars and with 
various species of tlie Pomaceje as ttieir alternating- liosts. 



100 



Shade Teees. 



ISTone of these rusts are considered serious and treatments are 
seldom given. The blister rust of the white pine, however, 
which attacks the stems is most dangerous and demands most 
vigorous treatment. (See page 103.) 

2. DISEASES OF THE STEMS. 

The diseases of the stems maj be arbitrarily grouped into 
(a) bark diseases, (b) heart rots, (c) sap rots, and (d) twig 
diseases. 




Fig. 37. Chestnut Bark Disease. Forest tree nearly dead. 
Note characteristic sprouts and dwarfed leaves on sur- 
viving branches. (Photo by Perley Spaulding.) 



Diseases of Shade and Forest Trees. 



101 



Chestnut Bakk Disease or Blight. 

This is probably the most serious tree disease in America 
at the present time. It is caused bj' a fungus (Diaporthe 
parasitica ^' Murrill) which lives parasitically in the bark, 
sending its minute thread-like processes in all directions from 
the point of attack until the trunk or branch is completely 
girdled. (Figs. 37, 38.) 

It is very doubtful if the fungus can gain entrance to a 
tree except through wounds, and it is probably carried from. 



M 




IfM- 


^Sb' ' -^ -^1 


''- . ' ■^'-0'^-'^''"'.C. 


f ''M- i 


iaBfe^-iVrt^ 




1 


5*V«it. • 


^-'M 


la^^^ti^:Py''^ . 


./;■ - _. ■■ y. 


'■ ■ ' i^K 


pjiHBpHa^^-i^rfl"^ '-^ '-j'W 


6 [ ';' 'Y ' -.■. 


'■%%■ 








%^^y--^::m:^:^:^- 


'1 


^B 


■';■;■- ^' ' . ■ .■ 


^■'■pjj 


^m •'^ 




.. W^^J 


■ d 


II:- •■:'"■ 


^j.^ 


Jfel 


«';.;■-■■ 


■L 



Fig. 38. Section of Cliestniit tree killed 

by blight with bark in successive 

stages of decay and pustules in 

which the winter spores 

are borne. ( Photo by 

J. F. Collins.) 

place to place by boring insects and by birds (especially wood- 
peckers). It is also carried on infected timber shipped into 



*The proper name of this fungus is at the present time a disputed point 
which will require further study before it can be definitely settled. 



102 . Shade Trees. 

uninfected territory. Many new points of infection have 
been traced to diseased nursery stock. E'urserj^men should 
Spread of ^^^e evcry caution to prevent the spread of the 
the disease. diseasc by keeping a careful oversight of their 
stock. Unfortunately, the disease cannot alv^ays be detected 
at the time of shipment, and therefore young trees should 
be kept under careful supervision by the grower. It is im- 
wise at this time to plant chestnut in this State, and growers 
in territory beyond the present range of the disease should 
be absolutely sure of the healthy character of the stock used 
for planting. The spread of the disease has been so rapid, 
the destruction of our chestnut growth so great, and the 
financial losses so heavy, that it has attracted more attention 
than any other plant disease in recent years. Large sums 
of money are being expended in fighting it, but up to the 
present time no satisfactory method has been devised. The 
planting of chestnuts in the infected districts is a waste of 
both time and money. 

Treatment. 

Individual trees and small plantings may be protected to 
some extent by frequently cutting out the diseased parts and 
painting the wounds with coal tar. In doing this all the 
prunings must be burned. When forest areas become af- 
fected their final destruction is practically certain, and the 
o^Tiers are advised to convert the entire chestnut growth into 
salable material as rapidly as possible. Otherwise it will 
prove a complete loss. Material too small for lumber should 
have the bark removed. All waste material should be burned 
at once. 

The severity of this disease, the rapidity of its spread, 
and the desire of the people to protect their trees have de- 
veloped a most fertile field for the quack tree-doctors who are 
claiming to cure trees by secret methods. These 

Tree fakirs. '=' . "^ . 

methods usually consist m putting secret prep- 
. arations under the bark or in the soil about the roots of 
the trees. Similar methods have been used for other tree 



Diseases of Shade and Forest Trees. 103 

diseases in various parts of the country, but without success. 
There are no such treatments for diseases of this character 
known to science, and the authors of these secret methods 
freely acknowledge that their treatments are not recognized 
by scientific workers. The public is cautioned against 
patronizing these people. 



White Pine Blister Rust. 

The blister rust (Feridermium strohi Klebahn" ) of the 
white pine, a European disease which has been introduced 
into this country and apparently stamped out, but which may 
be introduced again at any time, causes a spindle shaped, or 
sometimes irregular warty swelling on the gj.,„y^^„,^, 
trunks of seedlings and young trees and upon 
the young branches of older trees. (Fig. 39.) Those 
swellings do not occur until one or more years after the ni- 
fection, which makes it impossible to detect the disease in 
its earliest stages. As these swellings approach maturity 
they form on the surface rounded or elongated bodies measur- 
ing one-eighth to one-half inch across. The bodies have deli- 
cate, whitish membrane coverings beneath which may be seen 
masses of orange-colored spores. This membrane ruptures, 
allowing the spores to escape (April to June), but may per- 
sist for some time after the spores have been carried away. 
If the spores are carried to gooseberries or cur- Aiteruating 
rants they attack the foliage and young shoots »'*"**''• 
and cause the "velvet rust" which produces two kinds of 
spores, one kind by which the fungus can spread on the 
gooseberries and currants and another by which it is returned 
to the white pines. The disease is of very little importance 
on the gooseberries and currants, but is very destructive on 
the white and other of the five-leaved pines. It attacks none 
of those with two or three needles. 



*Periaermium stroM Klebahn of the white and other five-leaved pines is the 
same as Cronartium ribicola Diet, of the cui-rant and gooseberry. 



104 



Shade Trees. 




Fig. 39. _ White Pine Blister Enst. A. A four-year-old tree with 
the disease; B. Leaf of Ribes aureum showing nredospore 
stage; C. Portion of same enlarged; D. Leaf of 
Eibes (imericanum showing teleutospore stage. 
(From Bui. 206, Bureau of Plant In- 
dustry, U. S. Dept. Agricul.) 



Diseases of Shade and Forest Teees. 105 

AVithiii the past few years the demand for white i3iues for 
reforestation and for ornamental plantings has been so great 
that large numbers of the seedlings have been imported from 
Euroj)e. The disease has been introduced on these seedlings 
and distributed to many localities in the United States, but 
fortunately has been kept in subjection. The disease is very 
destructive to seedlings and youno; trees and, ,^ ^ 
while not always destructive, is very injurious tiveness. 
on the older trees. Therefore we should use the greatest 
caution to prevent its getting a foothold in this country. 



Treatment. 

It is not advisable to plant five-leaved pines of European 
origin. Always use American grown seedlings. Even then 
the plants should be carefully examined from time to time, 
and in case the disease appears they should be destroyed im- 
mediately by burning. There is no known remedy for the 
disease, and absolutely no safe course to pursue other than 
burning the diseased plants. 



CoKAL Spots. 

The coral spots on the bark of trees and shrubs are due 
to fungi belonging to the genus JSTectria. They are readily 
recognized bv the small brightly colored red or orange fruit- 
ing bodies. There are a number of species, but the most 
important is N. cinnabarinna (Tode) Er. which attacks the 
maple, horse-chestnut and many other deciduous trees. The 
fungus gains entrance to its host through wounds, gradually 
spreads, forming well defined cankers within 
which will be found the highly colored fruiting 
bodies. When once well established it may spread rapidly 
from plant to plant and become epidemic. This fungus 
also attacks currant bushes and pear trees. 



106 Shade Tkees. 



Treatment. 

The only practical method of control consists in cntting 
and burning diseased parts. 



Black Knots. 

These nnsightlv growths occnr on the twigs and leaves of 
some trees. Among the most important are those on the 
plums and cherries which are caused by the fungus (Ploiv- 
rightia morbosa Sacc), and those upon the hazel caused by 
the fungus (Cryptosporella anomala Pk.). 



Treatment. 

They are of no very great importance on shade trees, but 
can be controlled by cutting out and burning early in the 
fall and by spraying with copper sulphate or lime-sulphuv 
before the buds open in the spring. 



Witches' Brooms. 

These conspicuous and unsightly growths are quite com- 
mon and are due to the attacks of both fungi and insects 
which cause the formation of masses of short twigs and are 
sometimes mistaken for mistletoe growths. (See page 107.) 
The most common and most conspicuous is the one on the 
hackberry. (Celtis occidentalis L.) This is so common 
that it is extremely difficult to find a tree that does not have 
them, and many people consider them a characteristic growth 
of the hackberry. However, they are a disease, and if the 
tree is kept free from them, it makes a very beautiful growth. 
The disease is said to be due to two parasitic organisms, a 
powdery mildew {Spoerotheca pliytoptophUa Kell and S. W.) 
and a mite (Eriophyes sp.) 



Diseases of Sh.vde aintd Forest Trees. 107 

Some of the species of the cedar rust (Gymnosporangium) 
(see page 99) and the leaf curl fungi (see page 98) are also 
the cause of witches' brooms which die and are broken out 
by the wind storms, thus leaving irregular and unsightly 
trees. 

2')-i'atment. 

As witches' broom is more unsightly than harmful, it may 
be ignored or the trees may be pruned as for other defects. 



jNIistletoes. 

Mistletoes are true flowering plants which live parasitically 
upon many of our native trees. The common ilmerican 
mistletoe {Phoradendron fiavescens (Pursh) jSTutt. is rare in 
Xew Jersey, occurring mostly on the black gum and red 
maple. AVhere very abundant they are considered serious 
enemies. It will be readily recognized that parasites of this 
kind will naturally retard and stunt the growth of the tree. 
They are also the cause of unsightly swellings and some 
of them cause witches' brooms. Their life is usually shorter 
than that of the trees on Avhich they live, and 
when they die and decay they leave cavities SXn'^e"'"™ 
which are especially favorable for the introduc- 
tion of pathogenic fungi and other organisms of disease. 
]\Iistietoes are so rare in this State that most people will be 
inclined to look upon them as objects of interest rather than 
as serious pests. 

Treatment. 

They can be controlled by priming out the diseased parts 
and painting the wounds with white lead or coal tar. 



108 



Shade Trees. 



Heart Rots. 

Heart rots are extremely destructive to both living and 
dead trees. They are due to a number of fungi, many of 
v^hich are both parasitic and sai3rophytic. The fact that 
many of these organisms will live on the dead wood from 
which they readily pass to the living trees makes it very 
important that all such dead and decaying material be re- 
moved and burned. 



White Heaet Rot. 

This is a true disease caused by the false tinder fungus, 
Fomes igniarius (L.) Gillet. It attacks the beech, aspen, 
willows, maples, birches, walnuts, oaks, hickory, 
apple, etc. The organism gains entrance 
through wounds and grows in the heart wood which it trans- 



Trees 

attacked- 




Fig 40. Fomes igniarius on a living aspen. (From Bui. 
149, Bureau of Plant Industry, U. S. Dept. of Agricul.) 



forms into a white pulpy mass bounded by one or more black 
layers. During this period of decay the disease cannot be 
detected from the outside but after the fungus has progressed 
two or three feet from the point of entrance it comes to the 



Diseases of Shade akd Forest Trees. 109 

surface and produces its siDorophores or fruiting bodies. (Fig. 
40.) These fruiting bodies usually occur at the original 
wound and are rather conspicuous but variable in shape, size 
and color. They may be described as hoof- Fruiting 
shaped, almost as thick as broad, and some- »>odies. 
times measuring as much as twelve inches in diameter. The 
upper surface is smooth when j^oung, becoming concentri- 
cally marked as it grows older. The outer part is hard, 
brown, gradually becoming black and cracked with age. The 
pores within which the spores are produced are formed in 
layers on the underside. The under surface is gray or red- 
browai in color, varying with the season. The disease works 
rather slowly, gradually weakening the tree until it is broken 
by storms. It is one of the most widely distributed of tree 
diseases and causes enormous losses which, from their wide 
geographical distribution and wide range of host plants, are 
extremely difficult to estimate. See also Polyporus sp., p. 111. 



Treatment. 

The most satisfactory treatment for shade and ornamental 
trees is preventive. When trees become infected the dis- 
eased parts should be removed and the wounds properly 
cared for as recommended on page 44. 



Red Heart Rot. 

This rot is caused by the parasitic fungus (Polyporus sul- 
■phureus (Bull.) Fr.). It attacks the oaks, chestnut, maples, 
walnuts, locusts, alder, ash, poplar, willows, apple, etc., and 
is widely distributed throughout ISTorth T,.epj, 
America and Europe. It gains entrance ^^^tacKea. 
through wounds and causes the heart wood to rot and be- 
come reddish brown or black, the color varying somewhat 
with the host plant. After a period of growth within the 
wood, it comes to the surface producing a number of large 



110 



Shade Teees. 



shelving sporophores or fruiting bodies (Fig. 41) frequently 
overlapping. When young the upper surfaces are a bright 
orange-red with a brighter red rim, very moist, and turn 




Fig. 41. Polyporus sulfureus on red oak. (Photo by 
Dr. W. A. Murrill, N. Y. Botanic Garden. ) 



Fruitin 
bodies. 



brown when bruised. When mature they are hard, dry, 
brittle and sulphur colored. They are usually 
destroyed very early by insects. The treat- 
ment is the same as for the white heart rot. 

P. rohinice '" Murrill attacks the black locust through 
wounds and comj^letely destroys the heart wood of living 
trees. The rot begins at the center of the heart and spreads 

*P. rohinia; Mui'rill=:P. rimosus Berkeley. 



Diseases of Shade and Forest Trees. Ill 

radially, causing the wood to become soft and 
yellowish or brownish in color. The sporo- hearTrot. 
phores are large and shelving and usually al- 
most twice as wide laterally as from front to back. The 
])roper care of wounds will help to control the disease but it 
is frequently distributed by the locust borer. (See page 83.) 
The diseased ])arts should be removed and destroyed and the 
wounds treated. 

P. ju 11 i peri II us Schrenk attacks old red cedar trees caus- 
ing a white heart rot. The fungus probably gains extrance 
to thf tree through dead branches which are most common in 
old trees. The wood gradually loses its color, becomes 
whitish and eventually undergoes disintegration leaving 
holes through the center of branches and trunk. Fruiting 
bodies are seldom' formed. The removal of dead branches 
and diseased parts will reduce the possibility of infection. 
P. carneus JSTees. also causes a Avhite heart rot of both the 
red cedar and arboiTit^e. It has been reported in this 
State as occurring on dead logs but no doubt is Heart rots 
also parasitic. The disease is characterized by and*^arb^-' 
the formation of pockets or holes containing ^'"'^• 
more or less bro'^vn charcoal-like rotten wood. In advanced 
stages these holes frequently unite. It should be treated the 
same as the preceding. 

P. ohiusus Berk, causes a soft heart rot of certain species 
of the oak but is not of such great importance here as farther 
west. It is readily distributed by the oak borer (Prionoxys- 
tus robinice Peck). It spreads rapidly up and 
dov/n the trunk and branches causing the heart oak heart 
wood to become soft, white and brittle and very 
easily broken in slight storms. The sporophores are hoof- 
shaped, almost white when young, but changing with age to 
a light brown. 

P. fraxinophilus Pk. is the cause of an im- , , 

' ^ . . Asli rot. 

portant disease of the white ash in the Middle 

West. It occurs as far east as Albany, jSTew York, but has 

not been reported from ITew Jersey. 

P. squamosus (Huds) Fr. is not common and is known 



112 Shade Trees. 

White rot. ^^^^^' ^^^ ^^® northern part of the United States. 
It gains entrance to living trees through 
wounds, causing a white heart rot. It has been reported on 
maples, oaks, elm, basswood, willow and ash. 

Pohjstictus vesicolor (L.) Fr. (see below) is the cause of 
a soft heart rot of the catalpa. The disease slarts in the 
center of the trunk or branch, causing the wood to turn pale 
and finally a straw yellow color. The diseased wood becomes 
soft and pithy and easily broken. The disease can usually 
Catalpa ^6 rccogiiized by the holes which are formed 

heart rot. where diseased branches have been broken off. 

Trees in the open are not so likely to be attacked as those 
grown in crowded conditions which result in the natural 
dying of the lower branches. 



Treatment. 

Careful pruning and treatment of wounds will prove ample 
protection for shade and ornamental trees. 



Sap Rots. 

The sap rots are the cause of considerable losses, and al- 
though it is impossible to draw a sharp line of distinction 
between those which are parasitic and those which are sapro- 
phytic, the majority of the sap rot fungi must be considered 
primarily saprophytes. Among the most important are the 
following : 

The sap rot caused by the fungus {Polystictus versicolor 
(L.) Fr.) is a true saprophyte, except on the Catalpa (see 
above), and attacks cut and fallen timber of many kinds. 
Although more of a saprophyte than a para- 



posts, poies site, the wide distribution and ffreat abundance 
of this fungus demands that it should receive 
some attention in this publication. It is especially destruc- 
tive on railroad ties, posts and poles. It grows in the sap 
wood, causing a decay and eventually forming its charac- 



Diseases of Shade ais'd Forest Trees. 



ii; 



teristic thin, tongh, leathery, shelving sporophores. (Fig- 
42.) They are variable in size, frequently very numerous 
and o^'erlapping. The upper surface is marked with con- 




Fig. 42. Polystictus versicolor on dead bark. (From Eeport 
of Penn. Forestry, 1902, Plate XXII.) 

centric zones of various colors while the imder surface is 
usually white. The pores of the under surface, within which 
the spores are borne, are very small and regular. 

Another sap rot is caused by Polystictus per game nus Fr. 
It is usually found on dead trees and is quite common on 
trees that have been injured by fire. It also occurs on living 

8 



114 Shade Teees. 

oaks, red gum. maples, bircli, chestnut, hickory, tulip, poplar, 
. . black cherry, beech, willows and others, especi- 

Attaoks iu- "^ ' ' . . . ' / 

jured trees ally thosB that have been injured, and is widely 
distributed throughout [N^orth America. How- 
ever, it has been questioned whether this fungus ever occurs 
on the li^-ing parts of trees. The general appearance of the 
decay is very similar to that caused by P. versicolor. (Fig, 
42.) The fruiting bodies are leathery, generally white when 
young but growing gray with age, the upper surface slightly 
hairy and the lower surface purplish; the pores are small 
and tend to produce a ragged surface with age. 



Treatment. 

Protection from injury and the proper care of wounds 
will practically prevent the occurrence of this disease. 

P, hetuUnus (Bull) Fr. is the cause of a sap rot on several 
species of birch and other trees, but whether parasitic or 
saprophytic is a disputed point. The same is true of P. 
fomentarius (L.) Fr. 

Follies apvlanatus (Pers.) Wallr., one of the most con- 
spicuous of our shelving fungi is said to cause a sap rot 
disease on cottonwoods. However, on most trees it must be 
considered purely saprophytic. 

There are a large number of other sap rots 

^a*ithyf*^^ due to a number of species of fungi occurring 

on many species of trees. Most of them are 

saprophytic, but some of them are or may become parasitic, 

especially on trees which are weakened from other causes. 



3. DISEASES OF THE ROOTS. 

The diseases of roots are very imperfectly understood. 
They may be due to unfavorable soil conditions, or to fungi, 
or to both. Probably the most important of these diseases is 
the rot due to the fungus Armillaria mellea (Vahl.) Que- 



Diseases of Shade a:xd Forest Trees. 



115 



let, which is widely distributed throughout Xonh America. 
The fungus usually gains entrance through 
w-ounds, but some authorities claim that it will con""on 

root rot. 

attack uninjured roots. It causes a decay of 
the roots, thus cutting off the supply of water and food from 
the soil and eventually causing the death of the tree. In 
the roots and surrounding soil will be found the so-called 
"shoe strings"- — hard black strands of the fundus which 
branch and interlace, dra^v nourishment from the decaying 





m^^ 


^^^^■Ife 


Jm llfflH 


\li 


^^!!>\.^V^|^^ 


f- 




mmam 



Fig. 43. Armillaria mellea. Parasitic on the 

roots of many trees. (Courtesy of 

New York Botanic Garden.) 

wood, and finally give rise to the fruiting bodies. The fruit- 
ing bodies, a form of mushroom (Fig. 43) appear to grow 
from the soil, are honey colored, the upper surface viscid and 
specked with white ; the gills of the lower surface white and 
giving off great quantities of spores ; the stems are swollen 
at the base and have a distinct ring below the umbrella 
shaped top. 

Treatment. 

ISTewly cleared land in which this disease is prevalent 
should not be set to trees of anv kind. When the disease 



IIG Shade Teees. 

becomes abundant tliere is no successful method of control. 
Diseased trees should be burned, but it is not safe to plant 
young trees in the same soil. 



Gas. 
^ . . Iliuminatins: gas escaping from defective 

Gas injury. . . o o i o 

pipes impregnates the soil, poisons the roots 
and causes the death of trees. The remedy for this is evi- 
dent, but in replanting it is frequently necessary to remove 
the soil from a considerable area and refill with a fresh 
supply from outside sources. (See page 28.) 



4. DISEASES DUE TO ENVIRONMENT. 

Plants respond readily to their surroundings, and (in a 
state of nature, undisturbed by man) the best growths will 
always be found where the surroundings are most favorable. 
The most important natural factors which influence the 
growth of plants are soiL water and temperature. The soil 
may be unfavorable to plant gro^vth owing to the lack, or 
improper proportions, of food substances ; or it may be too 
shallow or may not hold the proper amount of water. The 
toater content of the soil is an important factor, varying 
with the requirements of the various species of plants. The 
amount of water that may be unfavorable for a tree will fre- 
quently be favorable for the organisms of disease. Tem- 
perature is also an imjDortant factor, both as causing direct 
injuries which may retard the growth of trees or cause their 
death, and by making it possible for fungi and other destruc- 
tive organisms to 2:ain entrance. 

S'inolce, gases, etc., are also the causes of many injuries 
and heavy losses. When trees stand close together, the ef- 
fects of smoke and free gases are first noticed in the tops, 
but in single trees the injuries msij be distributed through- 
out the crown. As in cases of poisoning by illuminating gas 
(page 20), the first symptoms are discoloration of the young 



Diseases of Shade aistd Foeest Teees. 117 

leaves followed by slow dying, reduction in the rate of 
growth of the twigs and, in fact, of the tree generally. 
Eventually the t^\'ig5 die and finally the branches and trunks. 
The different kinds of trees show varying degrees of re- 
sisrance and, therefore, trees in the vicinity of furnaces, 
snielrers, mills, etc., will not show an equal degree of injury 
from the central point ; some species of trees at considerable 
distances from the course of smoke and gas may be killed 
while i:)ther species very uear may continue to live for many 
years. "The order of susceptibility, beginning with the 
trees most easily killed, is as follows : * 

"White pine {Finns sirohus L.), Hemlock (Tsuga sp.). 
Scrub i^ine {Pinus virginiana Mill.), Pitch pine (Pinus 
rigida Mill.), Chestnut oak (Querciis prinus L.), Hickory 
(Hicoria sp.). Black-jack {Quercus viarilandica Muench.), 
^Vhite oak {Quercus alba L. ), Post oak {Quercus minor 
(]\Iarsh.) Sargent), Chestnut {Castanea dentata (Marsh.) 
Porkh. ), Spanish oak {Quercus digitata (Marsh.) Sud- 
W(irtli), Scarlet oak {Quercus coccinea Muench.), Tulip pop- 
lar {Liriodendron tulipifera L.), Maple {Acer sp.). Black 
gum {Nyssa sylraiica Marsh.)." 



Treatment. 

The injuries are greatest to leeward of the prevailing 
winds. They can be overcome in a great measure by the 
construction of tall smokestacks which will carry the in- 
jurious gases into the higher strata of air. Devices for con- 
densing the gases, such as passing through water, have been 
used with some degree of success. There is no satisfactory 
treatment so long as trees are exposed to the abnormal en- 
vironments. The causes must be removed. 

Dust from cement and other establishments has also proved 
to be the cause of some injuries. When cement dust settles 



♦Taken from Bulletin No. 1-10, Bureau of Plant Industry, U. S. Department 
of Agriculture. Diseases of Deciduous Forest Trees. Herman Von Sbreuk 
and Perley Spaulding. 



118 Shade Trees. 

on the foliage, and is wet by the rains it "sets'' and shuts 
ont the light to some extent and reduces the working effici- 
ency of the plant. 

5. OTHER DISEASES. 



Seed bed 
disease. 



"Damping off" is one of the most destruc- 
tive diseases of very young plants, especially 
coniferous trees. It is due to fungi which are semi-sapro- 
phytic in habit, living in wet, decaying organic matter, 
especially in manure. These organisms become especially 
active under the warm, moist conditions which are favorable 
for the germination of the seeds and for the growth of the 
young plants. The fungi attack these seedlings at the sur- 
face of the ground causing them to wilt, fall over and die. 
The fungi continue to live on the dead plants and spread to 
the living seedlings. The disease is especially prevalent in 
seed beds and in nature where the plants are growing in 
crowded conditions. These diseases are responsible in a 
great measure for the difficulties in growing coniferous seed- 
lings and other nursery stock in America. 



Treatment. 

The "damping oil;"' fungi can be controlled to some extent 
in various ways. (>ne of the most common practices is that 
of burning a large quantity of vegetable material on the 
surface of the bed before planting. Formalin disfection of 
the soil is also used extensively. By this method the beds 
are thoroughly prepared and then drenched with a formalin 
solution (1 jjart commercial formalin to 150 to 200 parts 
water) using three or four quarts to each square foot of bed 
surface. The beds should then be covered with burlap for 
24 hours and after that thoroughly aired for about a week. 
Tn some cases it may be necessary to make two or three ap- 
plications, dependent on the character of the soil. This 



Diseases of Shade axd Forest Trees. 119 

treatment must be used with care, as it will sometimes re- 
duce the germinating power of the seeds. 

Insects are the cause of many diseases, among the most 
interesting of which are the cecidia or galls. These ab- 
normal growths occur on roots, stems, leaves, flowers and 
fruits and are due to insect injuries, in most cases the insects 
making their homes for a considerable part of their lives 
within the li'alls. Some of them are very in- 

'^ , . -^ Galls not 

] uncus, but most of those occurring on trees often 

. '^ harmful. 

are considered oi littie importance. However, 
individual plants are frequently so seriously affected as to 
mar their beauty and no doubt reduce their vitality. The 
great regularity of shape, color and markings of these galls 
will always make them objects of great interest to both 
scientist and layman, and future studies will probably prove 
them to be the cause of greater injuries than we now at- 
tribute to them. Fortunately, owing to the migratory char- 
acter of the insects, most species of insect galls do not occur 
two or more years in succession on the same trees. Some 
few species can be sprayed to advantage with insecticides, 
but in most cases where the pests become troublesome it will 
be found necessary to prune and destroy the diseased parts 
before the insects emerge. 

Abnormal structures are also formed as a result of fungus, 
bacterial and mechanical injuries. 

Animal injuries of various kinds are frequently the open- 
ings by which fungi and other organisms of disease gain 
entrance to the host plants. Insects, birds, squirrels and 
other animals are also the distributers of many 
diseases bv makino- wounds and carryins: the promote 

<■' ~ I, o disease. 

organisms from ])lace to place. Storms also 
aid in the work of destruction by breaking branches and thus 
causing wounds which immediately become sources of infec- 
tion. 



120 Shade Teees. 



METHODS OF CONTROL. 

It will be readily seen that the treatment of trees must 
be prijnarily protective, rather than curative. It is impos- 
sible to use orchard methods in the forests and 

Prevention 

better than frequently impractical to use such methods on 

cure. <J -L 

shade and ornamental trees. Good forestry 
practice in the forest and proper care of shade and orna- 
mental trees will greatly reduce the ravages of many of these 
diseases. 

The heart and sap rots usually (probably always) origi- 
nate with wounds through which the organisms gain en- 
trance. Of course not all wounds give rise to diseases any 
more than all wounds of human beings and lower animals 

2;ive rise to blood poisoning, but all wounds 
induce must bc lookcd upou as points where infections 

decay. tit ic 

are likely to occur and therefore as sources of 
danger. Frequent inspection of shade and ornamental trees, 
the cutting out of broken branches, proper pruning, and the 
care of all wounds are important factors in preserving the 
beauty and contributing to longevity. (See page 26.) De- 
caying wood forms a most excellent garden for many fungi 
which are both saprophytic and parasitic in habit. It should 
alwa}'s be removed and burned. 

Spraying may be practiced to some extent for foliage dis- 
eases on shade and ornamental trees, especially small ones. 
Among the most im])ortant of the spraying mixtures is lime- 
sulphur which is used extensively for scale insects. It is 
also a fungicide and will reduce the organisms that winter 
on the stems and trunk. 

«„,.„,.„„. Bordeaux mixture is the old and reliable 

mixtures. fuugicide and can be used on most trees for 

foliage diseases. However, it is unsafe for some trees and 
has the disadvantage of discoloring the parts to which it is 
applied. Where the discolorations are undesirable, the am- 
moniacal-copper-carbonate solution can frequently be used to 



Diseases of Shade a]S'd Foeest Trees. 131 

advantage. Potassium sulphide solution is a very nseful 
remedy where it is desirable to protect ornamentals against 
jiowdery mildews and other superiicial fungi. 



FUNGICIDES. 

Bordeaux Mixture. 

Copper sulphate 2 to .5 pounds 

Quick lime 3 to 6 pounds 

Water 50 gallons 

This is one of the oldest and most reliable fungicides 
known. The lime is to prevent certain injuries which might 
otherwise arise from the use of copper sulphate and the 
amount should always be slightly in excess of the amount 
of the copper sulphate. The copper sulphate is dissolved in 
a small cjuantity of water by suspending the crystals in a bag 
at the surface. The lime is slacked in a small quantit}^ of 
water. Each mixture is then diluted to 25 gallons and the 
two are poured together. The copper sulphate may be dis- 
solved, and the lime slacked, and the two kept as stock for 
dilution and use as needed but the mixture will not keep 
after being poured together. The strength of Bordeaux mix- 
ture varies with the character of the foliage of the plants to 
be treated, since the foliage of many tender plants will be 
injured by it. 

Copper Sulpliate. 

One pound of copper sulphate dissolved in 25 gallons of 
water makes an excellent winter spray but cannot be used on 
plants when in foliage. 

Lime-SuIpJiur. 

This mixture has come into general use as a winter spray 
and has largely superseded copper sulphate since it serves as 
both a fungicide and an insecticide. The conrnercial prod- 



122 Shade Teees. 

uct used in the proportion of 1 gallon to 10 gallons cf water 
is very satisfactory, but cannot be used on foliage. For 
trees in leaf a mixture of 1 gallon in 30 gallons of water is 
as strong as is safe. This mixture can be made at home 
according to the formula given in our State and government 
publications, but most people find it more satisfactory to use 
the commercial product. 



Aramonia-copper-carhonatG mixture. 

Copper carbonate (i oz. 

Ammonia (26° Beaume) 3 pts. 

Water 50 gal. 

Dissolve the copper carbonate in the ammonia and dilute 
with water. This mixture has the advantage of not dis- 
coloring the foliage. It is rather unreliable and should be 
used with care and always tested on a single plant, or small 
part of a plant, before general application. 



Potassium sulphide. 

Potassium suljdiide (liver of sulfur), % to l^^ lbs. 
Water 50 gal. 

This treatment is very successful on the surface-growing 
fungi, such as the mildews, but of no value on the more 
vigorous parasites. 

Sprayers. 

Spraying pumps and machines are easily obtained of any 
seed house. For information regarding forms rnd sizes see 
page 88. 



Diseases of Shade and Forest Trees. 123 



A LIST OF PUBLICATIOIvS OlST THE CAEE OF SHADE TREES. 

Shade Trees in Towns and Cities. Wm Solotaroff. John 
Wiley & Sons, Kew York City. 

Tree Pruning. A. Descars. John Wilson & Son, Cam- 
bridge, jMass. 

Landscape Gardening as Applied to Home Decoration. 
Samnel T. Maynard. John Wiley & Sons, 'New York City. 

Care of Trees. B. E. Pernow. Henry Holt & Co., jSTew 
York City. 

The Pruning Boole. L. H. Bailey. The Macmillian Co., 
:N'ew York City. 

Concerning Insects Alone. 

Economic Entomology. John B. Smith. J. B. Lippin- 
cott Co., Philadelphia. 

Manual for the Study of Insects. John Henry Comstock. 
Comstock Pub. Co., Ithaca, JN^. Y. 

American Insects. Yernon L. Kellogg. Henry Holt & 
Co., ^ew York City. 

Insects Affecting ParTc and Woodland Trees, 2 Yol. E. 
P. Felt. New York State Museum Memoir S. X. Y. 
State Edncation Dept., Albany. 



Concerning Plant Diseases. 

Fungus Diseases of Plants. B. M. Dnggar. Ginn & Co., 
Boston. 

T'ext Book of the Diseases of Trees. Robert Hartig. 
Translated from the German by William Somerville and H. 
Marshall Ward, London, Eng. 

Diseases of Deciduous Forest Trees. H. von Schrenk and 
Perley Spanlding. Bulletin 149 Bureau of Plant Industry, 
TJ. S. Department of Agriculture. 



124 Shade Tkees. 

Diseases of Economic Plants. F. L. Stevens and J. G. 
Hall, l-leath & Co., Boston. 

Diseases of Ornamental Trees. Haven Metcalf. Tear 
Book U. S. Department of Agriculture, 1907. 

Diseases of Shade and Ornamental Trees. B. T. Gallo- 
way and A. F. Wood.s. Year Book U. S. Department of 
Agriculture, 1890. 

The Control of the Chestnut Bark Disease. Haven Met- 
calf and J. F. Collins. Farmers' Bulletin 467 U. S. De- 
partment of Agriculture. 



Index. 



Black-faced figures indicate specific descriptions. 



PAGES. 
A. 

Abrasions 21, 36, 44 

Abrasion moulding 36 

Abused trees 11 

Aid to tree owners 6,43 

Ailanthus 9, 13, 56 

Alder, diseases of 109 

Animonia-copper-carbonate 

mixture 120,122 

Anthracnoses 9" 

Antiseptics 44, 45 

Arborvitse 53, 55 

diseases of Ill 

Arrangement of trees 15 

Arsenate of lead 68,72,87,89 

Ash 9, 13, 14, 53-55, 57 

diseases of ...99,109,111,112 
Aspen, diseases of 108 

B. 

Bag-worm 69 

Balsam 55 

Banding trees 68,69 

Bark beetles S3 

Bark may be cleaned 87 

Basket worm, see Mg-wonn. 
Basswood 8, 13, 43, 57 

diseases of Il2 

insects affecting 76 

Beauty in trees 12 

Beech 14, 54, 57 

diseases of 108. 114 

Bibliography 123, 124 

Bilsted. see red gum. 

Birch 53 

diseases of 98, lOS. 114 

Birds, disease distributors.. 119 

Black knots 106 

Books about shade trees. . 123, 124 
Bordeaux mixture. .96, 97, 120, 121 

Borers 82-85 

Box elder 8, 63 



PAGES. 

Braces, tree 42, 49 

Buckeye, see horse chestnut. 

Building, dangers of 27 

Butchery, tree 40, 43 

Buttonwood, see sycamore. 



Carbon bisulphide 74, 83 

Care of trees 21, 43, 87, 120 

Care of wounds 44 

Catalpa 5S 

diseases of 96. 112 

Cavities 42, 44, 47, 48 

treatment of 45 

Cedar apples 99 

Cedar, red 55, 56 

diseases of 99, 107, 111 

Chestnut 14, 59 

diseases of 96 

101, 102, 109, 114, 117 

horse, see horse chestnut. 

Climate of New Jersey 7 

Climbing spurs 35 

Conifers, see evergreens. 
Construction and building. . 27 

Control of diseases 120 

Co-operation 26, 51, 52 

Copper sulphate 97,98.121 

Coral spots 105 

Cotton batting bands 68,69 

Cottonwood, see poplar. 

Cottony maple scale 72 

Crotches, split 42, 49 

Crown IS, 20. 38 

Curb lines 17,32-34.50.54 

Cypress 53 

D. 

Decay 13, 43, 44. 47, 48, 93 

Defoliation 88 

Disease, causes of 93 

Diseases, tree 93-122 

Doctoring, tree 42,43,47 

125 



126 



Index. 



, PAGES. 

Dogwood 53 

diseases of 98 

Drop worm, see bag-iconn. 

Drouth 15 

Dust cement 117 

E. 

Electric linemen 35 

Electric wires 31-36 

Elm 8, 13, 14, 38, 43, 54, 55, 59 

diseases of 96,112 

insects affecting .... 67, 73, 79 
Environment, diseases due 

to 116-118 

Evergreens 13, 43, 53, 55 

diseases of 118 

insects affecting S6 

F. 

Fall planting 15 

Fall web worm 75 

Fertilizer 25 

Filling 42, 45, 47, 48 

Fir 56 

Fire, disease induced by.... 113 

Foliage, diseases of 95-1 0>0 

Food, tree 24, 25 

Footing 11, 17, 20» 23 

Fornralin 118 

Frost, susceptibility of trees 

to 8 

Fruiting bodies 94, 105 

109, 110, 113, 115 

Fungi 93-122 

Fungicides 96-98, 120, 121 

G. 

Galls 119 

Gas 28-30, 116, 117 

Ginkgo 8, 13, 60 

Grade, street, changes in... 

50-52, 62 

Gratings 23, 24 

Grass underneath trees. . 24, 53, 54 
Growing space, see footing. 

Growth, rapidity of 8 

Guards .. .5, 11, 19, 21, 23, 27, 28, 36 

Guys 27 

Gum, black 61 

diseases of 107, 117 

red or sweet 8,12-14,61 

diseases of 114 

H. 

Hackberry 13, 14, 56. 61 

diseases of 106 



PAGES. 

Hardiness of trees 8 

Hawthorn 53 

Heading in 40 

Head room under trees 18 

Heart rots 10S-H2, 120 

Hemlock 53 

diseases of 99, 117 

Hickory 14 

diseases of 108, 114, 117 

insects affecting 83,84 

Hole, the 18 

Holly 56 

Horse bites 21, 36 

Horse chestnut 8, 12, 13, 61 

diseases of 96, 105 

I. 

Improvements, municipal 

anticipated 52 

Injuries 21, 26-36, 93, 116, 119 

Insects 67-91, 106, 119 

Insecticides 68, 69, 72-76, 78 

SO, 81, 83-89 
Insects attack weakened 
trees 82 

K. 

Kerosene emulsion 73, 75, 78 

L. 

Larch 53 

Large trees 53 

Lawn mower 36, 54 

Lawn trees 53, 56 

Lead arsenate, see arsenate of lead. 

Leaf burn S 

Leaf cast 99 

Leaf curl 98, 107 

Leaf spots 95,96 

Lice, plant 85, 86 

Light, influence of upon 

trees 37 

Lime 27 

Lime-sulphur ... .78, 80, 97, 98, 121 
Linden, see hasswood. 

Location of trees 17 

Locust 9. 13, 14, 56, 62 

diseases of 109, 110 

insects affecting 14,83 

M. 

Magnolia 53 

Maple 9-12, 38, 43, 63 

ash leaf, see how elder. 

Norway 8,13,14.56,63 

red 8. 13. 56. 63 



Index. 



127 



I'AGES. 
Maple — ■ 

silver, or white 8, 9, 13 

14, 49, 56, 63 

sugar 54 

diseases of 63,96, 105 

107-10i9, 112, 114, 117 

insects atTecting 72-74 

76, 78, 82, 85, 86 

Mildews 97, 98 

Mistletoes 107 

Mortar 27 

Mountain ash 53 

Mulberry 9 

N. 

Neatness in trees 9 

Nourishment 24, 25, 53 

Nursery stock, diseased 102 

O. 

Oak 54-56,64 

bur 64 

chestnut 56, 64 

English 64 

pin 8, 13, 14, 38, 54, 56, 64 

red 8, 13, 56, 64 

scarlet 13, 14, 56, 64 

swamp white 64 

white 8, 13, 64 

diseases of 97, 98, 108 

109, 111, 112, 114, 117 

insects affecting 68,69 

74, 75, 111 
Old trees, treatment of. . .40, 41, 49 
Oyster shell bark louse 74 



Parasites 93 

Paris green 68,69,72,76,85 

Pavements 8, 24 

Pepperidge, see hlack gum. 

Pine 56 

maritime 56 

Jersey (scrub) diseases 

of 99, 117 

pitch, diseases of 99, 117 

Scotch, diseases of 99 

white, diseases of 103, 117 

white, insects affecting. . 87 
Plane, see sycamore. 

Planting time 15 

Planting, tree 19, 20 

Police regulations 21, 36 

Poplar 9, 13, 14, 56 

diseases of 98, 99, 109, 114 

insects affecting 78 



PAGES. 

Potassium sulphide .... 98, 121, 122 

Powdery mildews 97, 98, 106 

Pruning 8, 18, 20, 37-44, 102 

interior 37, 43 

Prune, time to 43 

Public service 26, 35, 52 

R. 

Red bud ■ 53 

Red gum 12 

Roots 17-20, 25-28, 38 

disea.ses of 114-116 

Root suckers 14 

Rusts 99 



Salt 28 

San Jose scale 79 

Sap lifter 39, 41 

Saprophytes 93 

Sap rots 112-114, 120 

Scalecide 77, 80, 81 

Scurfy scale 7S 

Seasliore trees 55 

Serviceberry 53 

Sliade endurance 54 

Shade, too much 9, 16 

Shade Tree Commissions ... 26, 36 
43, 51, 52 

Shade Tree Federation 53 

Sidev/alks 17, 50 

Silverbell 53 

Size of street trees 17 

Smoke 116 

Soil 7, 14, 19. 116 

Sourwood 53 

Spacing 5, 16, 17 

Sparrows, English 74 

Splits, in trees 42, 49 

Sporopliores 94, 113 

Spraying . . .68, 69, 72, 73, 75-77, 78 
80, 81, 86-88, 96, 97-99, 106, 120 
See also insecticides and 
fungicides. 

cost of 91 

machines ,. 88-90, 122 

Spring planting 15 

Spruce 54-56 

Spurs, climbing 35 

Stakes, tree 19-21 

Starvation, signs of 25 

Starving trees 24 

Stems, diseases of 100,114 

Sticky bands 68,69 



cu^w^. 



128 



Index. 



' PAGES. 
Street trees, requirements 

of 7 

Sycamore 8, 13, 14, 55, 56, 64 

diseases of 97 



96 



factor 



Tar spots . . 

Temperature, 

disease 

Topping 

Treatment of cavities 

Tree fakirs 43 

Trees, cultivation of 

Trees not recommended. ... 9, 13 

Trees, what to plant. .8, 13, 14, 56 

Tulip poplar 8,13,38,65 

diseases of 114, 117 

insects affecting SO 

Tupelo, see Macli gum. 



lib 

40 
45 

102 
8 



U. 

Uniformity in trees. 



Value of trees 



.12 



26 



\v. 

Walnut 14 

diseases of 96,108,109 

Water 24, 116 

Well, tree 50, 51 

Wliale oil soap 73,75 

78, 80, 81, 85-87 
White marked tussock 

motli 

White pine blister rust... IDS' 

White pine weevil 

Willow 

diseases of 9 

108, 109, 112 

Wind breaks 5 

Wiring rules 3 

Wires, electric 3 

W^itches' broom 61 

Wood leopard moth .... 
Wounds 42,44,47 49,50 



68 
105 

87 

14 
, 99 
, 114 
3, 55 
5, 36 
1-36 
, 106 

73 
', 120 



Yellow-wood 



53 



LBAp'I3 



LIBRARY OF CONGRESS 



DDDDTESbSD? 



